diff --git a/config/alfresco/subsystems/Authentication/kerberos/kerberos-authentication-context.xml b/config/alfresco/subsystems/Authentication/kerberos/kerberos-authentication-context.xml
index 9fd0d41ffd..66bbc2b2fe 100644
--- a/config/alfresco/subsystems/Authentication/kerberos/kerberos-authentication-context.xml
+++ b/config/alfresco/subsystems/Authentication/kerberos/kerberos-authentication-context.xml
@@ -87,6 +87,9 @@
       <property name="jaasConfigEntryName">
          <value>${kerberos.authentication.cifs.configEntryName}</value>
       </property>
+      <property name="disableNTLM">
+         <value>true</value>
+      </property>
    </bean>
 
 </beans>
\ No newline at end of file
diff --git a/source/java/org/alfresco/filesys/auth/cifs/AlfrescoCifsAuthenticator.java b/source/java/org/alfresco/filesys/auth/cifs/AlfrescoCifsAuthenticator.java
index 3bf73c25cb..72e4baf044 100644
--- a/source/java/org/alfresco/filesys/auth/cifs/AlfrescoCifsAuthenticator.java
+++ b/source/java/org/alfresco/filesys/auth/cifs/AlfrescoCifsAuthenticator.java
@@ -26,9 +26,6 @@ package org.alfresco.filesys.auth.cifs;
 
 import java.security.NoSuchAlgorithmException;
 
-import javax.transaction.Status;
-import javax.transaction.UserTransaction;
-
 import net.sf.acegisecurity.Authentication;
 
 import org.alfresco.filesys.alfresco.AlfrescoClientInfo;
@@ -42,6 +39,7 @@ import org.alfresco.jlan.smb.server.SMBSrvSession;
 import org.alfresco.jlan.util.HexDump;
 import org.alfresco.repo.security.authentication.NTLMMode;
 import org.alfresco.repo.security.authentication.ntlm.NTLMPassthruToken;
+import org.alfresco.repo.transaction.RetryingTransactionHelper;
 
 /**
  * Alfresco Authenticator Class
@@ -94,7 +92,7 @@ public class AlfrescoCifsAuthenticator extends CifsAuthenticatorBase
      * @param sess Server session
      * @param alg Encryption algorithm
      */
-    public int authenticateUser(ClientInfo client, SrvSession sess, int alg)
+    public int authenticateUser(final ClientInfo client, final SrvSession sess, final int alg)
     {
         // Check that the client is an Alfresco client
       
@@ -138,7 +136,6 @@ public class AlfrescoCifsAuthenticator extends CifsAuthenticatorBase
         // Check if this is a guest logon
         
         int authSts = AUTH_DISALLOW;
-        UserTransaction tx = null;
         
         try
         {
@@ -172,24 +169,30 @@ public class AlfrescoCifsAuthenticator extends CifsAuthenticatorBase
             else if ( getNTLMAuthenticator().getNTLMMode() == NTLMMode.MD4_PROVIDER)
             {
                 // Start a transaction
+                authSts = doInTransaction(new RetryingTransactionHelper.RetryingTransactionCallback<Integer>()
+                {
+
+                    public Integer execute() throws Throwable
+                    {
+                        // Perform local MD4 password check
+                        return doMD4UserAuthentication(client, sess, alg);
+                    }
+                });
               
-                tx = createTransaction();
-                tx.begin();
-                
-                // Perform local MD4 password check
-                
-                authSts = doMD4UserAuthentication(client, sess, alg);
             }
             else
             {
                 // Start a transaction
-                
-                tx = createTransaction();
-                tx.begin();
+                authSts = doInTransaction(new RetryingTransactionHelper.RetryingTransactionCallback<Integer>()
+                {
+
+                    public Integer execute() throws Throwable
+                    {
+                        // Perform passthru authentication password check
+                        return doPassthruUserAuthentication(client, sess, alg);
+                    }
+                });
               
-                // Perform passthru authentication password check
-                
-                authSts = doPassthruUserAuthentication(client, sess, alg);
             }
             
             // Check if the logon status indicates a guest logon
@@ -217,34 +220,6 @@ public class AlfrescoCifsAuthenticator extends CifsAuthenticatorBase
           if ( logger.isDebugEnabled())
             logger.debug( ex);
         }
-        finally
-        {
-            // Commit the transaction
-            
-            if ( tx != null)
-            {
-                try
-                {
-                    // Commit or rollback the transaction
-                    
-                    if ( tx.getStatus() == Status.STATUS_MARKED_ROLLBACK)
-                    {
-                        // Transaction is marked for rollback
-                        
-                        tx.rollback();
-                    }
-                    else
-                    {
-                        // Commit the transaction
-                        
-                        tx.commit();
-                    }
-                }
-                catch ( Exception ex)
-                {
-                }
-            }
-        }
         
         // Check for an administrator logon
         
diff --git a/source/java/org/alfresco/filesys/auth/cifs/CifsAuthenticatorBase.java b/source/java/org/alfresco/filesys/auth/cifs/CifsAuthenticatorBase.java
index 3bb68dd05a..f53df4d83a 100644
--- a/source/java/org/alfresco/filesys/auth/cifs/CifsAuthenticatorBase.java
+++ b/source/java/org/alfresco/filesys/auth/cifs/CifsAuthenticatorBase.java
@@ -24,8 +24,6 @@
  */
 package org.alfresco.filesys.auth.cifs;
 
-import javax.transaction.UserTransaction;
-
 import net.sf.acegisecurity.Authentication;
 
 import org.alfresco.config.ConfigElement;
@@ -48,6 +46,7 @@ import org.alfresco.repo.security.authentication.AuthenticationComponent;
 import org.alfresco.repo.security.authentication.MD4PasswordEncoder;
 import org.alfresco.repo.security.authentication.MD4PasswordEncoderImpl;
 import org.alfresco.repo.security.authentication.ntlm.NLTMAuthenticator;
+import org.alfresco.repo.transaction.RetryingTransactionHelper;
 import org.alfresco.service.cmr.repository.NodeRef;
 import org.alfresco.service.cmr.repository.NodeService;
 import org.alfresco.service.cmr.security.AuthenticationService;
@@ -348,49 +347,28 @@ public abstract class CifsAuthenticatorBase extends CifsAuthenticator implements
      * @param client
      *            ClientInfo
      */
-    protected final void getHomeFolderForUser(ClientInfo client)
+    protected final void getHomeFolderForUser(final ClientInfo client)
     {
         // Check if the client is an Alfresco client, and not a null logon
-      
-        if ( client instanceof AlfrescoClientInfo == false ||
-        		client.isNullSession() == true)
-          return;
-        
-        AlfrescoClientInfo alfClient = (AlfrescoClientInfo) client;
-        
+
+        if (client instanceof AlfrescoClientInfo == false || client.isNullSession() == true)
+            return;
+
+        final AlfrescoClientInfo alfClient = (AlfrescoClientInfo) client;
+
         // Get the home folder for the user
-        
-        UserTransaction tx = getTransactionService().getUserTransaction();
-        NodeRef homeSpaceRef = null;
-        
-        try
+
+        doInTransaction(new RetryingTransactionHelper.RetryingTransactionCallback<Object>()
         {
-            tx.begin();
-            homeSpaceRef = (NodeRef) getNodeService().getProperty(getPersonService().getPerson(client.getUserName()), ContentModel.PROP_HOMEFOLDER);
-            alfClient.setHomeFolder( homeSpaceRef);
-            tx.commit();
-        }
-        catch (Throwable ex)
-        {
-            try
+
+            public Object execute() throws Throwable
             {
-                tx.rollback();
+                NodeRef homeSpaceRef = (NodeRef) getNodeService().getProperty(
+                        getPersonService().getPerson(client.getUserName()), ContentModel.PROP_HOMEFOLDER);
+                alfClient.setHomeFolder(homeSpaceRef);
+                return null;
             }
-            catch (Throwable ex2)
-            {
-                logger.error("Failed to rollback transaction", ex2);
-            }
-            
-             //          Re-throw the exception
-            if (ex instanceof RuntimeException)
-            {
-                throw (RuntimeException) ex;
-            }
-            else
-            {
-                throw new RuntimeException("Error during execution of transaction.", ex);
-            }
-        }
+        });
     }
     
     /**
@@ -400,58 +378,29 @@ public abstract class CifsAuthenticatorBase extends CifsAuthenticator implements
      *            String
      * @return String
      */
-    protected final String mapUserNameToPerson(String userName)
+    protected final String mapUserNameToPerson(final String userName)
     {
-        // Get the home folder for the user
-        
-        UserTransaction tx = getTransactionService().getUserTransaction();
-        String personName = null;
-        
-        try
+        return doInTransaction(new RetryingTransactionHelper.RetryingTransactionCallback<String>()
         {
-            tx.begin();
-            personName = getPersonService().getUserIdentifier( userName);
-            tx.commit();
 
-            // Check if the person exists
-            
-            if (personName == null) {
-                
-                tx = getTransactionService().getNonPropagatingUserTransaction( false);
-                tx.begin();
-                
-                getPersonService().getPerson( userName);
-                personName = getPersonService().getUserIdentifier( userName);
-                
-                tx.commit();
-            }
-        }
-        catch (Throwable ex)
-        {
-            try
+            public String execute() throws Throwable
             {
-                tx.rollback();
+                // Get the home folder for the user
+
+                String personName = getPersonService().getUserIdentifier(userName);
+
+                // Check if the person exists
+
+                if (personName == null)
+                {
+                    // Force creation of a person if possible
+                    getPersonService().getPerson(userName);
+                    personName = getPersonService().getUserIdentifier(userName);
+                    return personName == null ? userName : personName;
+                }
+                return personName;
             }
-            catch (Throwable ex2)
-            {
-                logger.error("Failed to rollback transaction", ex2);
-            }
-            
-            // Re-throw the exception
-            
-            if (ex instanceof RuntimeException)
-            {
-                throw (RuntimeException) ex;
-            }
-            else
-            {
-                throw new RuntimeException("Error during execution of transaction.", ex);
-            }
-        }
-        
-        // Return the person name
-        
-        return personName;
+        });
     }
     
     /**
@@ -545,7 +494,7 @@ public abstract class CifsAuthenticatorBase extends CifsAuthenticator implements
      * 
      * @return TransactionService
      */
-    protected final TransactionService getTransactionService()
+    private final TransactionService getTransactionService()
     {
         return this.transactionService;
     }
@@ -565,62 +514,48 @@ public abstract class CifsAuthenticatorBase extends CifsAuthenticator implements
      * @param cInfo
      *            ClientInfo
      */
-    protected final void checkForAdminUserName(ClientInfo cInfo) {
-        
+    protected final void checkForAdminUserName(final ClientInfo cInfo)
+    {
+
         // Check if the user name is an administrator
 
-        UserTransaction tx = createTransaction();
+        doInTransaction(new RetryingTransactionHelper.RetryingTransactionCallback<Object>()
+        {
 
-        try {
-            tx.begin();
+            public Object execute() throws Throwable
+            {
+                if (cInfo.getLogonType() == ClientInfo.LogonNormal
+                        && getAuthorityService().isAdminAuthority(cInfo.getUserName()))
+                {
 
-            if ( cInfo.getLogonType() == ClientInfo.LogonNormal && getAuthorityService().isAdminAuthority(cInfo.getUserName())) {
-                
-                // Indicate that this is an administrator logon
+                    // Indicate that this is an administrator logon
 
-                cInfo.setLogonType(ClientInfo.LogonAdmin);
+                    cInfo.setLogonType(ClientInfo.LogonAdmin);
+                }
+                return null;
             }
-            tx.commit();
-        }
-        catch (Throwable ex) {
-            try {
-                tx.rollback();
-            }
-            catch (Throwable ex2) {
-                logger.error("Failed to rollback transaction", ex2);
-            }
-
-            // Re-throw the exception
-
-            if ( ex instanceof RuntimeException) {
-                throw (RuntimeException) ex;
-            }
-            else {
-                throw new RuntimeException("Error during execution of transaction.", ex);
-            }
-        }
+        });
     }
     
     /**
-     * Create a transaction, this will be a wrteable transaction unless the system is in read-only mode. return
-     * UserTransaction
+     * Does work in a transaction. This will be a writeable transaction unless the system is in read-only mode.
      * 
-     * @return the user transaction
+     * @param callback
+     *            a callback that does the work
+     * @return the result, or <code>null</code> if not applicable
      */
-    protected final UserTransaction createTransaction()
+    protected <T> T doInTransaction(RetryingTransactionHelper.RetryingTransactionCallback<T> callback)
     {
         // Get the transaction service
-        
+
         TransactionService txService = getTransactionService();
-        
+
         // DEBUG
-        
-        if ( logger.isDebugEnabled())
+
+        if (logger.isDebugEnabled())
             logger.debug("Using " + (txService.isReadOnly() ? "ReadOnly" : "Write") + " transaction");
-        
-        // Create the transaction
-        
-        return txService.getUserTransaction( txService.isReadOnly() ? true : false);
+
+        return txService.getRetryingTransactionHelper().doInTransaction(callback, txService.isReadOnly());
     }
 
     /**
diff --git a/source/java/org/alfresco/filesys/auth/cifs/EnterpriseCifsAuthenticator.java b/source/java/org/alfresco/filesys/auth/cifs/EnterpriseCifsAuthenticator.java
index a1e39796c0..60ea1bc532 100644
--- a/source/java/org/alfresco/filesys/auth/cifs/EnterpriseCifsAuthenticator.java
+++ b/source/java/org/alfresco/filesys/auth/cifs/EnterpriseCifsAuthenticator.java
@@ -41,8 +41,6 @@ import javax.security.auth.callback.UnsupportedCallbackException;
 import javax.security.auth.login.LoginContext;
 import javax.security.auth.login.LoginException;
 import javax.security.sasl.RealmCallback;
-import javax.transaction.Status;
-import javax.transaction.UserTransaction;
 
 import org.alfresco.config.ConfigElement;
 import org.alfresco.error.AlfrescoRuntimeException;
@@ -80,6 +78,7 @@ import org.alfresco.jlan.util.DataPacker;
 import org.alfresco.jlan.util.HexDump;
 import org.alfresco.repo.security.authentication.NTLMMode;
 import org.alfresco.repo.security.authentication.ntlm.NLTMAuthenticator;
+import org.alfresco.repo.transaction.RetryingTransactionHelper;
 import org.ietf.jgss.Oid;
 
 /**
@@ -634,7 +633,7 @@ public class EnterpriseCifsAuthenticator extends CifsAuthenticatorBase implement
      * @param reqPkt SMBSrvPacket
      * @exception SMBSrvException
      */
-    public void processSessionSetup(SMBSrvSession sess, SMBSrvPacket reqPkt)
+    public void processSessionSetup(final SMBSrvSession sess, final SMBSrvPacket reqPkt)
         throws SMBSrvException
     {
         //  Check that the received packet looks like a valid NT session setup andX request
@@ -646,18 +645,21 @@ public class EnterpriseCifsAuthenticator extends CifsAuthenticatorBase implement
         
         if ( reqPkt.getParameterCount() == 13)
         {
-            UserTransaction tx = null;
-            
             try
             {
                 // Start a transaction
-                
-                tx = createTransaction();
-                tx.begin();
 
-                //  Process the hashed password session setup
-                    
-                doHashedPasswordLogon( sess, reqPkt);
+                doInTransaction(new RetryingTransactionHelper.RetryingTransactionCallback<Object>()
+                {
+
+                    public Object execute() throws Throwable
+                    {
+                        // Process the hashed password session setup
+
+                        doHashedPasswordLogon(sess, reqPkt);
+                        return null;
+                    }
+                });
             }
             catch ( Exception ex)
             {
@@ -665,34 +667,6 @@ public class EnterpriseCifsAuthenticator extends CifsAuthenticatorBase implement
                 
                 throw new SMBSrvException( SMBStatus.NTAccessDenied, SMBStatus.ErrDos, SMBStatus.DOSAccessDenied);
             }
-            finally
-            {
-                // Commit the transaction
-                
-                if ( tx != null)
-                {
-                    try
-                    {
-                        // Commit or rollback the transaction
-                        
-                        if ( tx.getStatus() == Status.STATUS_MARKED_ROLLBACK)
-                        {
-                            // Transaction is marked for rollback
-                            
-                            tx.rollback();
-                        }
-                        else
-                        {
-                            // Commit the transaction
-                            
-                            tx.commit();
-                        }
-                    }
-                    catch ( Exception ex)
-                    {
-                    }
-                }
-            }
             
             // Hashed password processing complete
             
@@ -704,21 +678,21 @@ public class EnterpriseCifsAuthenticator extends CifsAuthenticatorBase implement
         int maxBufSize = reqPkt.getParameter(2);
         int maxMpx     = reqPkt.getParameter(3);
         int vcNum      = reqPkt.getParameter(4);
-        int secBlobLen = reqPkt.getParameter(7);
+        final int secBlobLen = reqPkt.getParameter(7);
         int capabs     = reqPkt.getParameterLong(10);
 
         //  Extract the client details from the session setup request
 
         int dataPos = reqPkt.getByteOffset();
-        byte[] buf = reqPkt.getBuffer();
+        final byte[] buf = reqPkt.getBuffer();
 
         //  Determine if ASCII or unicode strings are being used
             
-        boolean isUni = reqPkt.isUnicode();
+        final boolean isUni = reqPkt.isUnicode();
 
         //  Make a note of the security blob position
         
-        int secBlobPos = dataPos;
+        final int secBlobPos = dataPos;
         
         //  Extract the clients primary domain name string
 
@@ -764,7 +738,7 @@ public class EnterpriseCifsAuthenticator extends CifsAuthenticatorBase implement
 
         //  Create the client information and store in the session
 
-        ClientInfo client = new AlfrescoClientInfo();
+        final ClientInfo client = new AlfrescoClientInfo();
         client.setDomain(domain);
         client.setOperatingSystem(clientOS);
         
@@ -786,13 +760,11 @@ public class EnterpriseCifsAuthenticator extends CifsAuthenticatorBase implement
         //  Process the security blob
         
         byte[] respBlob = null;
-        boolean isNTLMSSP = false;
-        
-        UserTransaction tx = null;
+        final boolean isNTLMSSP;
         
         try
         {
-        	
+        	           
             // Check if the blob has the NTLMSSP signature
             
             if ( secBlobLen >= NTLM.Signature.length) {
@@ -803,39 +775,36 @@ public class EnterpriseCifsAuthenticator extends CifsAuthenticatorBase implement
               while ( idx < NTLM.Signature.length && buf[secBlobPos + idx] == NTLM.Signature[ idx])
                 idx++;
               
-              if ( idx == NTLM.Signature.length)
-                isNTLMSSP = true;
+              isNTLMSSP = ( idx == NTLM.Signature.length);
             }
-            
+            else {
+              isNTLMSSP = false;                
+            }
+
             // Start a transaction
             
-            tx = createTransaction();
-            tx.begin();
-            
-            // Process the security blob
-            
-            if ( isNTLMSSP == true)
+            respBlob = doInTransaction(new RetryingTransactionHelper.RetryingTransactionCallback<byte[]>()
             {
-                //  Process an NTLMSSP security blob
-    
-                respBlob = doNtlmsspSessionSetup( sess, client, buf, secBlobPos, secBlobLen, isUni);
-            }
-            else
-            {
-                //  Process an SPNEGO security blob
-                
-                respBlob = doSpnegoSessionSetup( sess, client, buf, secBlobPos, secBlobLen, isUni);
-            }
-        }
-        catch (SMBSrvException ex)
-        {
-            //  Cleanup any stored context
+
+                public byte[] execute() throws Throwable
+                {
+                    // Process the security blob
+
+                    if (isNTLMSSP)
+                    {
+                        // Process an NTLMSSP security blob
+
+                        return doNtlmsspSessionSetup(sess, client, buf, secBlobPos, secBlobLen, isUni);
+                    }
+                    else
+                    {
+                        // Process an SPNEGO security blob
+
+                        return doSpnegoSessionSetup(sess, client, buf, secBlobPos, secBlobLen, isUni);
+                    }
+                }
+            });
             
-            sess.removeSetupObject( client.getProcessId());
-            
-            //  Rethrow the exception
-            
-            throw ex;
         }
         catch ( Exception ex)
         {
@@ -847,34 +816,6 @@ public class EnterpriseCifsAuthenticator extends CifsAuthenticatorBase implement
             
             throw new SMBSrvException( SMBStatus.NTAccessDenied, SMBStatus.ErrDos, SMBStatus.DOSAccessDenied);
         }
-        finally
-        {
-            // Commit the transaction
-          
-            if ( tx != null)
-            {
-                try
-                {
-                    // Commit or rollback the transaction
-                    
-                    if ( tx.getStatus() == Status.STATUS_MARKED_ROLLBACK)
-                    {
-                        // Transaction is marked for rollback
-                        
-                        tx.rollback();
-                    }
-                    else
-                    {
-                        // Commit the transaction
-                        
-                        tx.commit();
-                    }
-                }
-                catch ( Exception ex)
-                {
-                }
-            }
-        }
 
         // Debug
         
@@ -1046,11 +987,11 @@ public class EnterpriseCifsAuthenticator extends CifsAuthenticatorBase implement
         //  Pack the security blob
 
         int pos = respPkt.getByteOffset();
-        buf = respPkt.getBuffer();
+        byte[] buf1 = respPkt.getBuffer();
 
         if ( respBlob != null)
         {
-            System.arraycopy( respBlob, 0, buf, pos, respBlob.length);
+            System.arraycopy( respBlob, 0, buf1, pos, respBlob.length);
             pos += respBlob.length;
         }
         
@@ -1059,9 +1000,9 @@ public class EnterpriseCifsAuthenticator extends CifsAuthenticatorBase implement
         if ( isUni)
             pos = DataPacker.wordAlign(pos);
 
-        pos = DataPacker.putString("Java", buf, pos, true, isUni);
-        pos = DataPacker.putString("Alfresco CIFS Server " + sess.getServer().isVersion(), buf, pos, true, isUni);
-        pos = DataPacker.putString(getCIFSConfig().getDomainName(), buf, pos, true, isUni);
+        pos = DataPacker.putString("Java", buf1, pos, true, isUni);
+        pos = DataPacker.putString("Alfresco CIFS Server " + sess.getServer().isVersion(), buf1, pos, true, isUni);
+        pos = DataPacker.putString(getCIFSConfig().getDomainName(), buf1, pos, true, isUni);
         
         respPkt.setByteCount(pos - respPkt.getByteOffset());
     }
diff --git a/source/java/org/alfresco/filesys/auth/cifs/PassthruCifsAuthenticator.java b/source/java/org/alfresco/filesys/auth/cifs/PassthruCifsAuthenticator.java
index 77d7fa641c..32c7e6a7d7 100644
--- a/source/java/org/alfresco/filesys/auth/cifs/PassthruCifsAuthenticator.java
+++ b/source/java/org/alfresco/filesys/auth/cifs/PassthruCifsAuthenticator.java
@@ -28,9 +28,6 @@ import java.util.ArrayList;
 import java.util.Hashtable;
 import java.util.List;
 
-import javax.transaction.Status;
-import javax.transaction.UserTransaction;
-
 import org.alfresco.config.ConfigElement;
 import org.alfresco.error.AlfrescoRuntimeException;
 import org.alfresco.filesys.alfresco.AlfrescoClientInfo;
@@ -68,6 +65,7 @@ import org.alfresco.model.ContentModel;
 import org.alfresco.repo.security.authentication.AuthenticationComponent;
 import org.alfresco.repo.security.authentication.NTLMMode;
 import org.alfresco.repo.security.authentication.ntlm.NLTMAuthenticator;
+import org.alfresco.repo.transaction.RetryingTransactionHelper;
 import org.alfresco.service.cmr.repository.NodeRef;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -158,14 +156,14 @@ public class PassthruCifsAuthenticator extends CifsAuthenticatorBase implements
      * @param alg int
      * @return int
      */
-    public int authenticateUser(ClientInfo client, SrvSession sess, int alg)
+    public int authenticateUser(final ClientInfo client, final SrvSession sess, int alg)
     {
         // Check that the client is an Alfresco client
       
         if ( client instanceof AlfrescoClientInfo == false)
             return ICifsAuthenticator.AUTH_DISALLOW;
         
-        AlfrescoClientInfo alfClient = (AlfrescoClientInfo) client;
+        final AlfrescoClientInfo alfClient = (AlfrescoClientInfo) client;
         
         // The null session will only be allowed to connect to the IPC$ named pipe share.
 
@@ -181,224 +179,196 @@ public class PassthruCifsAuthenticator extends CifsAuthenticatorBase implements
 
         // Start a transaction
         
-        UserTransaction tx = createTransaction();
-        int authSts = AUTH_DISALLOW;
-        
-        try
-        {
-            // Start the transaction
-          
-            tx.begin();
-          
-            // Check if the client is already authenticated, and it is not a null logon
-            
-            if ( alfClient.getAuthenticationToken() != null && client.getLogonType() != ClientInfo.LogonNull)
+        return doInTransaction(new RetryingTransactionHelper.RetryingTransactionCallback<Integer>(){
+
+            public Integer execute() throws Throwable
             {
-                // Use the existing authentication token
+                int authSts = AUTH_DISALLOW;
                 
-                getAuthenticationComponent().setCurrentUser( mapUserNameToPerson( client.getUserName()));
-    
-                // Debug
-                
-                if ( logger.isDebugEnabled())
-                    logger.debug("Re-using existing authentication token");
-                
-                // Return the authentication status
-                
-                return client.getLogonType() != ClientInfo.LogonGuest ? AUTH_ALLOW : AUTH_GUEST; 
-            }
-            
-            // Check if this is a guest logon
-            
-            if ( client.isGuest() || client.getUserName().equalsIgnoreCase(getGuestUserName()))
-            {
-                // Check if guest logons are allowed
-                
-                if ( allowGuest() == false)
-                    return AUTH_DISALLOW;
-                
-                //  Get a guest authentication token
-                
-                doGuestLogon( client, sess);
-                
-                // Indicate logged on as guest
-                
-                authSts = AUTH_GUEST;
-                
-                // DEBUG
-                
-                if ( logger.isDebugEnabled())
-                    logger.debug("Authenticated user " + client.getUserName() + " sts=" + getStatusAsString(authSts));
-                
-                // Return the guest status
-                
-                return authSts;
-            }
-    
-            // Find the active authentication session details for the server session
-    
-            PassthruDetails passDetails = m_sessions.get(sess.getUniqueId());
-    
-            if (passDetails != null)
-            {
-    
                 try
                 {
-    
-                    // Authenticate the user by passing the hashed password to the authentication server
-                    // using the session that has already been setup.
-    
-                    AuthenticateSession authSess = passDetails.getAuthenticateSession();
-                    authSess.doSessionSetup(client.getDomain(), client.getUserName(), null, client.getANSIPassword(), client.getPassword(), 0);
-    
-                    // Check if the user has been logged on as a guest
-    
-                    if (authSess.isGuest())
-                    {
-    
-                        // Check if the local server allows guest access
-    
-                        if (allowGuest() == true)
-                        {
-                            //  Get a guest authentication token
-                            
-                            doGuestLogon( client, sess);
-                            
-                            // Allow the user access as a guest
-    
-                            authSts = ICifsAuthenticator.AUTH_GUEST;
-    
-                            // Debug
-    
-                            if (logger.isDebugEnabled())
-                                logger.debug("Passthru authenticate user=" + client.getUserName() + ", GUEST");
-                        }
-                    }
-                    else
-                    {
-                        // Map the passthru username to an Alfresco person
-    
-                        String username = client.getUserName();
-                        String personName = getPersonService().getUserIdentifier( username);
-                        
-                        if ( personName != null)
-                        {
-                            // Use the person name as the current user
-                            
-                            alfClient.setAuthenticationToken( getAuthenticationComponent().setCurrentUser(personName));
-                            
-                            // DEBUG
-                            
-                            if ( logger.isDebugEnabled())
-                                logger.debug("Setting current user using person " + personName + " (username " + username + ")");
-    
-                            // Allow the user full access to the server
-    
-                            authSts = ICifsAuthenticator.AUTH_ALLOW;
-    
-                            // Debug
-    
-                            if (logger.isDebugEnabled())
-                                logger.debug("Passthru authenticate user=" + client.getUserName() + ", FULL");
-                        }
-                        else if ( logger.isDebugEnabled())
-                            logger.debug("Failed to find person matching user " + username);
-                    }
-                }
-                catch (Exception ex)
-                {
-    
-                    // Debug
-    
-                    logger.error(ex);
-                }
-    
-                // Keep the authentication session if the user session is an SMB session, else close the
-                // session now
-    
-                if ((sess instanceof SMBSrvSession) == false)
-                {
-    
-                    // Remove the passthru session from the active list
-    
-                    m_sessions.remove(sess.getUniqueId());
-    
-                    // Close the passthru authentication session
-    
-                    try
-                    {
-    
-                        // Close the authentication session
-    
-                        AuthenticateSession authSess = passDetails.getAuthenticateSession();
-                        authSess.CloseSession();
-    
-                        // DEBUG
-    
-                        if (logger.isDebugEnabled())
-                            logger.debug("Closed auth session, sessId=" + authSess.getSessionId());
-                    }
-                    catch (Exception ex)
-                    {
-    
-                        // Debug
-    
-                        logger.error("Passthru error closing session (auth user)", ex);
-                    }
-                }
-            }
-            else
-            {
-    
-                // DEBUG
-    
-                if (logger.isDebugEnabled())
-                    logger.debug("  No PassthruDetails for " + sess.getUniqueId());
-            }
-        }
-        catch ( Exception ex)
-        {
-            //  DEBUG
-          
-            if ( logger.isDebugEnabled())
-                logger.debug( ex);
-            
-            // Return an access denied status
-            
-            return AUTH_DISALLOW;
-        }
-        finally
-        {
-            // Commit the transaction
-            
-            if ( tx != null)
-            {
-                try
-                {
-                    // Commit or rollback the transaction
+                    // Check if the client is already authenticated, and it is not a null logon
                     
-                    if ( tx.getStatus() == Status.STATUS_MARKED_ROLLBACK)
+                    if ( alfClient.getAuthenticationToken() != null && client.getLogonType() != ClientInfo.LogonNull)
                     {
-                        // Transaction is marked for rollback
+                        // Use the existing authentication token
                         
-                        tx.rollback();
+                        getAuthenticationComponent().setCurrentUser( mapUserNameToPerson( client.getUserName()));
+            
+                        // Debug
+                        
+                        if ( logger.isDebugEnabled())
+                            logger.debug("Re-using existing authentication token");
+                        
+                        // Return the authentication status
+                        
+                        return client.getLogonType() != ClientInfo.LogonGuest ? AUTH_ALLOW : AUTH_GUEST; 
+                    }
+                    
+                    // Check if this is a guest logon
+                    
+                    if ( client.isGuest() || client.getUserName().equalsIgnoreCase(getGuestUserName()))
+                    {
+                        // Check if guest logons are allowed
+                        
+                        if ( allowGuest() == false)
+                            return AUTH_DISALLOW;
+                        
+                        //  Get a guest authentication token
+                        
+                        doGuestLogon( client, sess);
+                        
+                        // Indicate logged on as guest
+                        
+                        authSts = AUTH_GUEST;
+                        
+                        // DEBUG
+                        
+                        if ( logger.isDebugEnabled())
+                            logger.debug("Authenticated user " + client.getUserName() + " sts=" + getStatusAsString(authSts));
+                        
+                        // Return the guest status
+                        
+                        return authSts;
+                    }
+            
+                    // Find the active authentication session details for the server session
+            
+                    PassthruDetails passDetails = m_sessions.get(sess.getUniqueId());
+            
+                    if (passDetails != null)
+                    {
+            
+                        try
+                        {
+            
+                            // Authenticate the user by passing the hashed password to the authentication server
+                            // using the session that has already been setup.
+            
+                            AuthenticateSession authSess = passDetails.getAuthenticateSession();
+                            authSess.doSessionSetup(client.getDomain(), client.getUserName(), null, client.getANSIPassword(), client.getPassword(), 0);
+            
+                            // Check if the user has been logged on as a guest
+            
+                            if (authSess.isGuest())
+                            {
+            
+                                // Check if the local server allows guest access
+            
+                                if (allowGuest() == true)
+                                {
+                                    //  Get a guest authentication token
+                                    
+                                    doGuestLogon( client, sess);
+                                    
+                                    // Allow the user access as a guest
+            
+                                    authSts = ICifsAuthenticator.AUTH_GUEST;
+            
+                                    // Debug
+            
+                                    if (logger.isDebugEnabled())
+                                        logger.debug("Passthru authenticate user=" + client.getUserName() + ", GUEST");
+                                }
+                            }
+                            else
+                            {
+                                // Map the passthru username to an Alfresco person
+            
+                                String username = client.getUserName();
+                                String personName = getPersonService().getUserIdentifier( username);
+                                
+                                if ( personName != null)
+                                {
+                                    // Use the person name as the current user
+                                    
+                                    alfClient.setAuthenticationToken( getAuthenticationComponent().setCurrentUser(personName));
+                                    
+                                    // DEBUG
+                                    
+                                    if ( logger.isDebugEnabled())
+                                        logger.debug("Setting current user using person " + personName + " (username " + username + ")");
+            
+                                    // Allow the user full access to the server
+            
+                                    authSts = ICifsAuthenticator.AUTH_ALLOW;
+            
+                                    // Debug
+            
+                                    if (logger.isDebugEnabled())
+                                        logger.debug("Passthru authenticate user=" + client.getUserName() + ", FULL");
+                                }
+                                else if ( logger.isDebugEnabled())
+                                    logger.debug("Failed to find person matching user " + username);
+                            }
+                        }
+                        catch (Exception ex)
+                        {
+            
+                            // Debug
+            
+                            logger.error(ex);
+                        }
+            
+                        // Keep the authentication session if the user session is an SMB session, else close the
+                        // session now
+            
+                        if ((sess instanceof SMBSrvSession) == false)
+                        {
+            
+                            // Remove the passthru session from the active list
+            
+                            m_sessions.remove(sess.getUniqueId());
+            
+                            // Close the passthru authentication session
+            
+                            try
+                            {
+            
+                                // Close the authentication session
+            
+                                AuthenticateSession authSess = passDetails.getAuthenticateSession();
+                                authSess.CloseSession();
+            
+                                // DEBUG
+            
+                                if (logger.isDebugEnabled())
+                                    logger.debug("Closed auth session, sessId=" + authSess.getSessionId());
+                            }
+                            catch (Exception ex)
+                            {
+            
+                                // Debug
+            
+                                logger.error("Passthru error closing session (auth user)", ex);
+                            }
+                        }
                     }
                     else
                     {
-                        // Commit the transaction
-                        
-                        tx.commit();
+            
+                        // DEBUG
+            
+                        if (logger.isDebugEnabled())
+                            logger.debug("  No PassthruDetails for " + sess.getUniqueId());
                     }
                 }
                 catch ( Exception ex)
                 {
+                    //  DEBUG
+                  
+                    if ( logger.isDebugEnabled())
+                        logger.debug( ex);
+                    
+                    // Return an access denied status
+                    
+                    return AUTH_DISALLOW;
                 }
-            }
-        }
-        
-        // Return the authentication status
+                
+                // Return the authentication status
 
-        return authSts;
+                return authSts;
+            }});
     }
 
     /**
@@ -954,7 +924,7 @@ public class PassthruCifsAuthenticator extends CifsAuthenticatorBase implements
      * @param type3Msg Type3NTLMMessage
      * @exception SMBSrvException 
      */
-    private final void doNTLMv1Logon(SMBSrvSession sess, ClientInfo client, Type3NTLMMessage type3Msg)
+    private final void doNTLMv1Logon(SMBSrvSession sess, final ClientInfo client, Type3NTLMMessage type3Msg)
         throws SMBSrvException
     {
         //  Get the type 2 message that contains the challenge sent to the client
@@ -963,7 +933,7 @@ public class PassthruCifsAuthenticator extends CifsAuthenticatorBase implements
         
         // Get the NTLM logon details
         
-        String userName = type3Msg.getUserName();
+        final String userName = type3Msg.getUserName();
         
         //  Check for a null logon
         
@@ -1016,70 +986,59 @@ public class PassthruCifsAuthenticator extends CifsAuthenticatorBase implements
                 {
                     // Wrap the service calls in a transaction
                     
-                    UserTransaction tx = createTransaction();
-                    
-                    try
+                    doInTransaction(new RetryingTransactionHelper.RetryingTransactionCallback<Object>()
                     {
-                        // Start the transaction
-                        
-                        tx.begin();
 
-                        // Map the passthru username to an Alfresco person
-                        
-                        NodeRef userNode = getPersonService().getPerson(userName);
-                        if ( userNode != null)
+                        public Object execute() throws Throwable
                         {
-                            // Get the person name and use that as the current user to line up with permission checks
-                            
-                            String personName = (String) getNodeService().getProperty(userNode, ContentModel.PROP_USERNAME);
-                            getAuthenticationComponent().setCurrentUser(personName);
-                            
-                            // DEBUG
-                            
-                            if ( logger.isDebugEnabled())
-                                logger.debug("Setting current user using person " + personName + " (username " + userName + ")");
-                        }
-                        else
-                        {
-                            // Set using the user name
-                            
-                            getAuthenticationComponent().setCurrentUser( userName);
+                            // Map the passthru username to an Alfresco person
 
-                            // DEBUG
-                            
-                            if ( logger.isDebugEnabled())
-                                logger.debug("Setting current user using username " + userName);
-                        }
-
-                        // Get the authentication token and store
-
-                        AlfrescoClientInfo alfClient = (AlfrescoClientInfo) client;
-                        alfClient.setAuthenticationToken( getAuthenticationComponent().getCurrentAuthentication());
-                        
-                        // Indicate that the client is logged on
-                        
-                        client.setLogonType( ClientInfo.LogonNormal);
-                        
-                        // Debug
-
-                        if (logger.isDebugEnabled())
-                            logger.debug("Passthru authenticate user=" + userName + ", FULL");
-                    }
-                    finally
-                    {
-                        // Commit the transaction
-                        
-                        if ( tx != null)
-                        {
-                            try {
-                                tx.commit();
-                            }
-                            catch (Exception ex)
+                            NodeRef userNode = getPersonService().getPerson(userName);
+                            if (userNode != null)
                             {
-                                // Sink it
+                                // Get the person name and use that as the current user to line up with permission
+                                // checks
+
+                                String personName = (String) getNodeService().getProperty(userNode,
+                                        ContentModel.PROP_USERNAME);
+                                getAuthenticationComponent().setCurrentUser(personName);
+
+                                // DEBUG
+
+                                if (logger.isDebugEnabled())
+                                    logger.debug("Setting current user using person " + personName + " (username "
+                                            + userName + ")");
                             }
+                            else
+                            {
+                                // Set using the user name
+
+                                getAuthenticationComponent().setCurrentUser(userName);
+
+                                // DEBUG
+
+                                if (logger.isDebugEnabled())
+                                    logger.debug("Setting current user using username " + userName);
+                            }
+
+                            // Get the authentication token and store
+
+                            AlfrescoClientInfo alfClient = (AlfrescoClientInfo) client;
+                            alfClient.setAuthenticationToken(getAuthenticationComponent().getCurrentAuthentication());
+
+                            // Indicate that the client is logged on
+
+                            client.setLogonType(ClientInfo.LogonNormal);
+
+                            // Debug
+
+                            if (logger.isDebugEnabled())
+                                logger.debug("Passthru authenticate user=" + userName + ", FULL");
+
+                            return null;
                         }
-                    }
+                    });
+
                 }
                 
                 // Update the client details