Index: lams_central/src/java/org/lamsfoundation/lams/authoring/ObjectExtractor.java
===================================================================
diff -u -r0d03e65a322050f17bfa0a1f34c4f20eae33953c -r62d0bb09a4512210d42ebd60885c7e1834c0cc5e
--- lams_central/src/java/org/lamsfoundation/lams/authoring/ObjectExtractor.java	(.../ObjectExtractor.java)	(revision 0d03e65a322050f17bfa0a1f34c4f20eae33953c)
+++ lams_central/src/java/org/lamsfoundation/lams/authoring/ObjectExtractor.java	(.../ObjectExtractor.java)	(revision 62d0bb09a4512210d42ebd60885c7e1834c0cc5e)
@@ -700,10 +700,20 @@
 	}
 
 	private void createRandomGrouping(RandomGrouping randomGrouping,Hashtable groupingDetails) throws WDDXProcessorConversionException{
-	    if (keyExists(groupingDetails, WDDXTAGS.LEARNERS_PER_GROUP))
-	        randomGrouping.setLearnersPerGroup(WDDXProcessor.convertToInteger(groupingDetails,WDDXTAGS.LEARNERS_PER_GROUP));
-		if (keyExists(groupingDetails, WDDXTAGS.NUMBER_OF_GROUPS))
-		    randomGrouping.setNumberOfGroups(WDDXProcessor.convertToInteger(groupingDetails,WDDXTAGS.NUMBER_OF_GROUPS));
+		// the two settings are mutually exclusive. Flash takes care of this, but we'll code it here too just to make sure.
+		Integer numLearnersPerGroup = WDDXProcessor.convertToInteger(groupingDetails,WDDXTAGS.LEARNERS_PER_GROUP);
+	    if (numLearnersPerGroup!=null && numLearnersPerGroup.intValue()>0) {
+	        randomGrouping.setLearnersPerGroup(numLearnersPerGroup);
+	        randomGrouping.setNumberOfGroups(null);
+	    } else {
+	    	Integer numGroups = WDDXProcessor.convertToInteger(groupingDetails,WDDXTAGS.NUMBER_OF_GROUPS);
+	    	if (numGroups!=null && numGroups.intValue()>0) {
+	    		randomGrouping.setNumberOfGroups(numGroups);
+	    	} else {
+	    		randomGrouping.setNumberOfGroups(null);
+	    	}
+    		randomGrouping.setLearnersPerGroup(null);
+	    }
 	}
 	private void createChosenGrouping(ChosenGrouping chosenGrouping,Hashtable groupingDetails) throws WDDXProcessorConversionException{
 		//no extra properties as yet
Index: lams_common/src/java/org/lamsfoundation/lams/learningdesign/RandomGrouper.java
===================================================================
diff -u -r418848d6f08966614dea2c347f66295efcae39d4 -r62d0bb09a4512210d42ebd60885c7e1834c0cc5e
--- lams_common/src/java/org/lamsfoundation/lams/learningdesign/RandomGrouper.java	(.../RandomGrouper.java)	(revision 418848d6f08966614dea2c347f66295efcae39d4)
+++ lams_common/src/java/org/lamsfoundation/lams/learningdesign/RandomGrouper.java	(.../RandomGrouper.java)	(revision 62d0bb09a4512210d42ebd60885c7e1834c0cc5e)
@@ -148,7 +148,7 @@
                                         List learners,
                                         boolean isInitialization)
     {
-        if(randomGrouping.getNumberOfGroups()!=null) {
+        if(randomGrouping.getNumberOfGroups()!=null && randomGrouping.getNumberOfGroups().intValue()>0) {
             return getNewGroupsByNumberOfGroups(randomGrouping, randomGrouping.getNumberOfGroups(), isInitialization);
         } else if(randomGrouping.getLearnersPerGroup()!=null && randomGrouping.getLearnersPerGroup().intValue()>0) {
             return getNewGroupsByLearnerPerGroup(randomGrouping,learners);
Index: lams_common/src/java/org/lamsfoundation/lams/learningdesign/service/LearningDesignValidator.java
===================================================================
diff -u -r19436c54fbbb9dabb0b769f18e32411f05bbc5e8 -r62d0bb09a4512210d42ebd60885c7e1834c0cc5e
--- lams_common/src/java/org/lamsfoundation/lams/learningdesign/service/LearningDesignValidator.java	(.../LearningDesignValidator.java)	(revision 19436c54fbbb9dabb0b769f18e32411f05bbc5e8)
+++ lams_common/src/java/org/lamsfoundation/lams/learningdesign/service/LearningDesignValidator.java	(.../LearningDesignValidator.java)	(revision 62d0bb09a4512210d42ebd60885c7e1834c0cc5e)
@@ -365,8 +365,10 @@
 	}
 	
 	/**
-	 * If this activity is an GroupingActivity and the grouping has some groups, then the number of groups must no exceed the desired number
-	 * of groups..
+	 * If this activity is an GroupingActivity, the number of groups in the grouping records is greater than 0 and 
+	 * the grouping has some groups, then the actual number of groups must no exceed the desired number of groups. 
+	 * If the desired number of groups is 0 then don't check the number of actual groups as there is no semantic limit
+	 * to the number of groups. 
 	 * 
 	 * @param parentActivity
 	 */
@@ -389,7 +391,7 @@
 					numGroupsInteger = grouping.getMaxNumberOfGroups();
 				}
 				int maxNumGroups = numGroupsInteger == null ? 0 : numGroupsInteger.intValue(); 
-				if ( grouping.getGroups() != null && grouping.getGroups().size() > maxNumGroups) {
+				if ( maxNumGroups > 0 && grouping.getGroups() != null && grouping.getGroups().size() > maxNumGroups) {
 					errors.add(new ValidationErrorDTO(ValidationErrorDTO.GROUPING_ACTIVITY_GROUP_COUNT_MISMATCH_ERROR_CODE, messageService.getMessage(ValidationErrorDTO.GROUPING_ACTIVITY_GROUP_COUNT_MISMATCH_KEY), activity.getActivityUIID()));
 				}
 			}