diff --git a/source/java/org/alfresco/repo/workflow/BPMEngineRegistry.java b/source/java/org/alfresco/repo/workflow/BPMEngineRegistry.java
index bbfebbb79a..fa2ebfaca7 100644
--- a/source/java/org/alfresco/repo/workflow/BPMEngineRegistry.java
+++ b/source/java/org/alfresco/repo/workflow/BPMEngineRegistry.java
@@ -38,7 +38,8 @@ import org.apache.commons.logging.LogFactory;
 public class BPMEngineRegistry
 {
     /** ID seperator used in global Ids */
-    private static final String ID_SEPERATOR = "-"; 
+    private static final String ID_SEPERATOR = "$"; 
+    private static final String ID_SEPERATOR_REGEX = "\\$"; 
     
     /** Logging support */
     private static Log logger = LogFactory.getLog("org.alfresco.repo.workflow");
@@ -159,7 +160,7 @@ public class BPMEngineRegistry
      */
     public static String[] getGlobalIdParts(String globalId)
     {
-        String[] parts = globalId.split(ID_SEPERATOR);
+        String[] parts = globalId.split(ID_SEPERATOR_REGEX);
         if (parts.length != 2)
         {
             throw new WorkflowException("Invalid Global Id '" + globalId + "'");
diff --git a/source/java/org/alfresco/repo/workflow/jbpm/JBPMEngine.java b/source/java/org/alfresco/repo/workflow/jbpm/JBPMEngine.java
index 43901614fb..bc3582f012 100644
--- a/source/java/org/alfresco/repo/workflow/jbpm/JBPMEngine.java
+++ b/source/java/org/alfresco/repo/workflow/jbpm/JBPMEngine.java
@@ -114,7 +114,7 @@ public class JBPMEngine extends BPMEngine
         "and ti.end is not null";
     
     // Workflow Path Seperators
-    private final static String WORKFLOW_PATH_SEPERATOR = "--";
+    private final static String WORKFLOW_PATH_SEPERATOR = "-";
     private final static String WORKFLOW_TOKEN_SEPERATOR = "@";
     
     // I18N labels
@@ -1198,7 +1198,7 @@ public class JBPMEngine extends BPMEngine
                 // map property to specific jBPM task instance field
                 if (key.equals(WorkflowModel.PROP_DUE_DATE))
                 {
-                    if (!(value instanceof Date))
+                    if (value != null && !(value instanceof Date))
                     {
                         throw new WorkflowException("Task due date '" + value + "' is invalid");
                     }
@@ -1216,7 +1216,7 @@ public class JBPMEngine extends BPMEngine
                 }
                 else if (key.equals(ContentModel.PROP_OWNER))
                 {
-                    if (!(value instanceof String))
+                    if (value != null && !(value instanceof String))
                     {
                         throw new WorkflowException("Task owner '" + value + "' is invalid");
                     }
diff --git a/source/java/org/alfresco/repo/workflow/jbpm/JBPMEngineTest.java b/source/java/org/alfresco/repo/workflow/jbpm/JBPMEngineTest.java
index 9617d15705..c5d376b6ba 100644
--- a/source/java/org/alfresco/repo/workflow/jbpm/JBPMEngineTest.java
+++ b/source/java/org/alfresco/repo/workflow/jbpm/JBPMEngineTest.java
@@ -131,7 +131,7 @@ public class JBPMEngineTest extends BaseSpringTest
         WorkflowDefinition workflowDef = getTestDefinition();
         WorkflowPath path = workflowComponent.startWorkflow(workflowDef.id, null);
         assertNotNull(path);
-        assertTrue(path.id.endsWith("--@"));
+        assertTrue(path.id.endsWith("-@"));
         assertNotNull(path.node);
         assertNotNull(path.instance);
         assertEquals(workflowDef.id, path.instance.definition.id);
@@ -154,7 +154,7 @@ public class JBPMEngineTest extends BaseSpringTest
         
         WorkflowPath path = workflowComponent.startWorkflow(workflowDef.id, params);
         assertNotNull(path);
-        assertTrue(path.id.endsWith("--@"));
+        assertTrue(path.id.endsWith("-@"));
         assertNotNull(path.node);
         assertNotNull(path.instance);
         assertEquals(workflowDef.id, path.instance.definition.id);
@@ -187,7 +187,7 @@ public class JBPMEngineTest extends BaseSpringTest
         
         WorkflowPath path = workflowComponent.startWorkflow(workflowDef.id, params);
         assertNotNull(path);
-        assertTrue(path.id.endsWith("--@"));
+        assertTrue(path.id.endsWith("-@"));
         assertNotNull(path.node);
         assertNotNull(path.instance);
         assertEquals(workflowDef.id, path.instance.definition.id);
@@ -279,7 +279,7 @@ public class JBPMEngineTest extends BaseSpringTest
         assertNotNull(paths);
         assertEquals(1, paths.size());
         assertEquals(instances.get(0).id, paths.get(0).instance.id);
-        assertTrue(paths.get(0).id.endsWith("--@"));
+        assertTrue(paths.get(0).id.endsWith("-@"));
     }