Index: lams_central/conf/language/lams/ApplicationResources.properties
===================================================================
diff -u -re17b56c0f30981cec5fe7d3c3c39dbc45707c166 -rdcb7977d20f0d29b809b2139a6814bc113c4485c
--- lams_central/conf/language/lams/ApplicationResources.properties	(.../ApplicationResources.properties)	(revision e17b56c0f30981cec5fe7d3c3c39dbc45707c166)
+++ lams_central/conf/language/lams/ApplicationResources.properties	(.../ApplicationResources.properties)	(revision dcb7977d20f0d29b809b2139a6814bc113c4485c)
@@ -459,6 +459,7 @@
 authoring.fla.branching.create.confirm =Transition from this activity already exists.\\nDo you want to create branching here?
 authoring.fla.transition.to.exists.error =Transition to this activity already exists.
 authoring.fla.circular.sequence.error =You are not allowed to have a circular sequence.
+authoring.fla.activity.in.container.error =You can not add this type of activity to an optional/support activity.
 authoring.fla.default.annotation.label.title =Label
 authoring.fla.region.fit.button.tooltip =Fit
 authoring.fla.new.folder.button =New
Index: lams_central/conf/language/lams/ApplicationResources_en_AU.properties
===================================================================
diff -u -re17b56c0f30981cec5fe7d3c3c39dbc45707c166 -rdcb7977d20f0d29b809b2139a6814bc113c4485c
--- lams_central/conf/language/lams/ApplicationResources_en_AU.properties	(.../ApplicationResources_en_AU.properties)	(revision e17b56c0f30981cec5fe7d3c3c39dbc45707c166)
+++ lams_central/conf/language/lams/ApplicationResources_en_AU.properties	(.../ApplicationResources_en_AU.properties)	(revision dcb7977d20f0d29b809b2139a6814bc113c4485c)
@@ -459,6 +459,7 @@
 authoring.fla.branching.create.confirm =Transition from this activity already exists.\\nDo you want to create branching here?
 authoring.fla.transition.to.exists.error =Transition to this activity already exists.
 authoring.fla.circular.sequence.error =You are not allowed to have a circular sequence.
+authoring.fla.activity.in.container.error =You can not add this type of activity to an optional/support activity.
 authoring.fla.default.annotation.label.title =Label
 authoring.fla.region.fit.button.tooltip =Fit
 authoring.fla.new.folder.button =New
Index: lams_central/web/authoring/authoring.jsp
===================================================================
diff -u -re17b56c0f30981cec5fe7d3c3c39dbc45707c166 -rdcb7977d20f0d29b809b2139a6814bc113c4485c
--- lams_central/web/authoring/authoring.jsp	(.../authoring.jsp)	(revision e17b56c0f30981cec5fe7d3c3c39dbc45707c166)
+++ lams_central/web/authoring/authoring.jsp	(.../authoring.jsp)	(revision dcb7977d20f0d29b809b2139a6814bc113c4485c)
@@ -53,6 +53,7 @@
 				BRANCHING_CREATE_CONFIRM : '<fmt:message key="authoring.fla.branching.create.confirm" />',
 				TRANSITION_TO_EXISTS_ERROR : '<fmt:message key="authoring.fla.transition.to.exists.error" />',
 				CIRCULAR_SEQUENCE_ERROR : '<fmt:message key="authoring.fla.circular.sequence.error" />',
+				ACTIVITY_IN_CONTAINER_ERROR : '<fmt:message key="authoring.fla.activity.in.container.error" />',
 				
 				// DecorationLib
 				DEFAULT_ANNOTATION_LABEL_TITLE : '<fmt:message key="authoring.fla.default.annotation.label.title" />',
Index: lams_central/web/includes/javascript/authoring/authoringActivity.js
===================================================================
diff -u -re17b56c0f30981cec5fe7d3c3c39dbc45707c166 -rdcb7977d20f0d29b809b2139a6814bc113c4485c
--- lams_central/web/includes/javascript/authoring/authoringActivity.js	(.../authoringActivity.js)	(revision e17b56c0f30981cec5fe7d3c3c39dbc45707c166)
+++ lams_central/web/includes/javascript/authoring/authoringActivity.js	(.../authoringActivity.js)	(revision dcb7977d20f0d29b809b2139a6814bc113c4485c)
@@ -987,6 +987,14 @@
 				});
 			}
 			if (container) {
+				// system activities can not be added to optional and support activities
+				if (activity instanceof ActivityDefs.GateActivity
+					|| activity instanceof ActivityDefs.GroupingActivity
+					|| activity instanceof ActivityDefs.BranchingEdgeActivity){
+					alert(LABELS.ACTIVITY_IN_CONTAINER_ERROR);
+					return false;
+				}
+				
 				if ($.inArray(activity, container.childActivities) == -1) {
 					$.each(activity.transitions.from, function(){
 						ActivityLib.removeTransition(this);
@@ -1013,6 +1021,7 @@
 		});
 		
 		GeneralLib.setModified(true);
+		return true;
 	},
 	
 
Index: lams_central/web/includes/javascript/authoring/authoringHandler.js
===================================================================
diff -u -re837b7b90d6cbae5ecf051b9c9ba61b3097e0c51 -rdcb7977d20f0d29b809b2139a6814bc113c4485c
--- lams_central/web/includes/javascript/authoring/authoringHandler.js	(.../authoringHandler.js)	(revision e837b7b90d6cbae5ecf051b9c9ba61b3097e0c51)
+++ lams_central/web/includes/javascript/authoring/authoringHandler.js	(.../authoringHandler.js)	(revision dcb7977d20f0d29b809b2139a6814bc113c4485c)
@@ -127,18 +127,22 @@
 		// finally transform the dragged elements
 		var transformation = object.items.shape.attr('transform');
 		object.items.transform('');
-		if (transformation.length > 0) {
-			// find new X and Y and redraw the object
-			var box = object.items.shape.getBBox(),
-				x = box.x,
+		
+		var box = object.items.shape.getBBox(),
+			originalCoordinates = {
+				x : box.x,
 				// adjust this coordinate for annotation labels
-				y = box.y + (object instanceof DecorationDefs.Label ? 6 : 0);
-			object.draw(x + transformation[0][1],
-						y + transformation[0][2]);
+				y : box.y + (object instanceof DecorationDefs.Label ? 6 : 0)
+			};
+		
+		if (transformation.length > 0) {
+			object.draw(originalCoordinates.x + transformation[0][1],
+						originalCoordinates.y + transformation[0][2]);
 		}
 		
 		// add space if dropped object is next to border
 		GeneralLib.resizePaper();
+		return originalCoordinates;
 	},
 	
 	
@@ -244,12 +248,18 @@
 					ActivityLib.removeActivity(activity);
 				} else {
 					// finalise movement - rewrite coordinates, see if the activity was not added to a container
-					HandlerLib.dropObject(activity);
+					
 
-					var translatedEvent = GeneralLib.translateEventOnCanvas(event),
+					var originalCoordinates = HandlerLib.dropObject(activity),
+						translatedEvent = GeneralLib.translateEventOnCanvas(event),
 						endX = translatedEvent[0],
-						endY = translatedEvent[1];
-					ActivityLib.dropActivity(activity, endX, endY);
+						endY = translatedEvent[1],
+						dropAllowed = ActivityLib.dropActivity(activity, endX, endY);
+					
+					if (!dropAllowed) {
+						// dropping the activity in this place is forbidden, revert the changes
+						activity.draw(originalCoordinates.x, originalCoordinates.y);
+					}
 				}
 			}
 			// start dragging the activity