Index: lams_flash/src/central/flash/org/lamsfoundation/lams/authoring/DesignDataModel.as
===================================================================
diff -u -rc00280fd5bd4810407e1105e5aad52218ff7bf6e -rfac001f56e1427654498b0888139e2dcfff7f6a6
--- lams_flash/src/central/flash/org/lamsfoundation/lams/authoring/DesignDataModel.as	(.../DesignDataModel.as)	(revision c00280fd5bd4810407e1105e5aad52218ff7bf6e)
+++ lams_flash/src/central/flash/org/lamsfoundation/lams/authoring/DesignDataModel.as	(.../DesignDataModel.as)	(revision fac001f56e1427654498b0888139e2dcfff7f6a6)
@@ -862,9 +862,10 @@
 		var myBranches:Array = new Array();
 		var hub = null;
 		var target = null;
+		var sequence = null;
 		
 		for(var i=0; i<br.length;i++){
-			if(br[i].targetUIID == UIID || br[i].hubUIID == UIID){
+			if(br[i].targetUIID == UIID || br[i].hubUIID == UIID || br[i].sequenceActivity.activityUIID == UIID){
 				myBranches.push(br[i]);
 			}
 			if(target != null && hub != null){
@@ -876,10 +877,14 @@
 				if(br[i].hubUIID == UIID){
 					hub = br[i];
 				}
+				if(br[i].sequenceActivity.activityUIID == UIID){
+					sequence = br[i].sequenceActivity;
+				}
 			}
 		}
 		branchObj.myBranches = myBranches;
 		branchObj.target = target;
+		branchObj.sequence = sequence;
 		branchObj.hub = hub;
 		return branchObj;
 	}
Index: lams_flash/src/central/flash/org/lamsfoundation/lams/authoring/cv/CanvasConnection.as
===================================================================
diff -u -r5b8b877a9e81a776b5af2cb4177c60e304e06dc6 -rfac001f56e1427654498b0888139e2dcfff7f6a6
--- lams_flash/src/central/flash/org/lamsfoundation/lams/authoring/cv/CanvasConnection.as	(.../CanvasConnection.as)	(revision 5b8b877a9e81a776b5af2cb4177c60e304e06dc6)
+++ lams_flash/src/central/flash/org/lamsfoundation/lams/authoring/cv/CanvasConnection.as	(.../CanvasConnection.as)	(revision fac001f56e1427654498b0888139e2dcfff7f6a6)
@@ -80,25 +80,17 @@
 		this.moveTo(_startPoint.x, _startPoint.y);
 		this.lineTo(_endPoint.x, _endPoint.y);
 		
-		Debugger.log('drawn line from:'+_startPoint.x+','+_startPoint.y+'to:'+_endPoint.x+','+_endPoint.y,4,'draw','CanvasTransition');
-		
 		// calc activity root angles
 		var fromAct_Angle:Number = Math.atan2(fromOTC.y, fromOTC.x);
 		var toAct_Angle:Number = Math.atan2(toOTC.y,toOTC.x);
 		
 		var fromAct_Deg:Number = convertToDegrees(fromAct_Angle);
 		var toAct_Deg:Number = convertToDegrees(toAct_Angle);
 		
-		Debugger.log("fromAct root angle: " + fromAct_Deg, Debugger.CRITICAL, "draw", "CanvasConnection");
-		Debugger.log("toAct root angle: " + toAct_Deg, Debugger.CRITICAL, "draw", "CanvasConnection");
-		
 		// gradient
 		var angle:Number = Math.atan2((_endPoint.y - _startPoint.y),(_endPoint.x - _startPoint.x));
 		var degs:Number = convertToDegrees(angle);
 		
-		Debugger.log("angle: " + angle, Debugger.CRITICAL, "draw", "CanvasConnection");
-		Debugger.log("degs: " + degs, Debugger.CRITICAL, "draw", "CanvasConnection");
-		
 		// get edgepoint for connected activities 
 		_fromAct_edgePoint = calcEdgePoint(degs, fromOTC.x, fromOTC.y, fromAct_Deg,  _startPoint);
 		_toAct_edgePoint = (degs >= 0) ? calcEdgePoint(degs - 180, toOTC.x, toOTC.y, toAct_Deg, _endPoint)
@@ -112,13 +104,6 @@
 			arrow_mc._y = (_startPoint.y + _endPoint.y)/2;
 		}
 		
-		Debugger.log("startPoint: (" + _startPoint.x + ", " + _startPoint.y + ")", Debugger.CRITICAL, "draw", "CanvasConnection");
-		Debugger.log("fromAct edge point: (" + _fromAct_edgePoint.x + ", " + _fromAct_edgePoint.y + ")", Debugger.CRITICAL, "draw", "CanvasConnection");
-		Debugger.log("toAct edge point: (" + _toAct_edgePoint.x + ", " + _toAct_edgePoint.y + ")", Debugger.CRITICAL, "draw", "CanvasConnection");
-		Debugger.log("endPoint: (" + _endPoint.x + ", " + _endPoint.y + ")", Debugger.CRITICAL, "draw", "CanvasConnection");
-		
-		Debugger.log("mid point: (" + _midPoint.x + ", " + _midPoint.y + ")", Debugger.CRITICAL, "draw", "CanvasConnection");
-		
 		arrow_mc._rotation = degs;
 		arrow_mc._visible = true;
 		
Index: lams_flash/src/central/flash/org/lamsfoundation/lams/authoring/cv/CanvasController.as
===================================================================
diff -u -rc00280fd5bd4810407e1105e5aad52218ff7bf6e -rfac001f56e1427654498b0888139e2dcfff7f6a6
--- lams_flash/src/central/flash/org/lamsfoundation/lams/authoring/cv/CanvasController.as	(.../CanvasController.as)	(revision c00280fd5bd4810407e1105e5aad52218ff7bf6e)
+++ lams_flash/src/central/flash/org/lamsfoundation/lams/authoring/cv/CanvasController.as	(.../CanvasController.as)	(revision fac001f56e1427654498b0888139e2dcfff7f6a6)
@@ -415,7 +415,7 @@
 		if(_canvasModel.isDragging){
 			ct.stopDrag();
 			
-			if (ct.hitTest(_canvasModel.getCanvas().bin) && !isTransitionTargetReadOnly(ct, Dictionary.getValue("cv_element_readOnly_action_del"))){
+			if(ct.hitTest(_canvasModel.getCanvas().bin) && !isTransitionTargetReadOnly(ct, Dictionary.getValue("cv_element_readOnly_action_del"))){
 				_canvasModel.getCanvas().removeTransition(ct.transition.transitionUIID); 
 			} else {
 				if (ct._x != ct.xPosition){
@@ -432,12 +432,15 @@
 		Debugger.log("branchRelease Transition:" + bc.branch.branchUIID, Debugger.GEN, "branchRelease", "CanvasController");
 		if(_canvasModel.isDragging){
 			bc.stopDrag();
-			
+			if(bc.hitTest(_canvasModel.getCanvas().bin) && !isBranchTargetReadOnly(bc, Dictionary.getValue("cv_element_readOnly_action_del"))){
+				_canvasModel.getCanvas().removeBranch(bc.branch.branchUIID); 
+			} else {
 				if (bc._x != bc.xPosition){
 					var t = _canvasModel.branchesDisplayed.remove(bc.branch.branchUIID);
 					t.removeMovieClip();
 					_canvasModel.setDirty();
 				}
+			}
 		}
 	
     }
@@ -567,6 +570,15 @@
 		}
 	}
 	
+	private function isBranchTargetReadOnly(bc:BranchConnector, action:String):Boolean {
+		if(_canvasModel.getActivityMCByUIID(bc.branch.targetUIID).activity.isReadOnly()) {
+			LFMessage.showMessageAlert(Dictionary.getValue('cv_trans_readOnly', [action])); // TODO: change dictionary message.
+			return true;
+		} else {
+			return false;
+		}
+	}
+	
 	private function isActivityReadOnly(ca:Object, action:String):Boolean {
 		if(Activity(ca.activity).isReadOnly()) {
 			LFMessage.showMessageAlert(Dictionary.getValue('cv_activity_readOnly', [action]));
Index: lams_flash/src/central/flash/org/lamsfoundation/lams/authoring/cv/CanvasModel.as
===================================================================
diff -u -r5b9f0b150997ca847824b7beba180b2a1006a68c -rfac001f56e1427654498b0888139e2dcfff7f6a6
--- lams_flash/src/central/flash/org/lamsfoundation/lams/authoring/cv/CanvasModel.as	(.../CanvasModel.as)	(revision 5b9f0b150997ca847824b7beba180b2a1006a68c)
+++ lams_flash/src/central/flash/org/lamsfoundation/lams/authoring/cv/CanvasModel.as	(.../CanvasModel.as)	(revision fac001f56e1427654498b0888139e2dcfff7f6a6)
@@ -623,7 +623,8 @@
 			Debugger.log('No validation errors, creating branch.......' + b,Debugger.GEN,'addActivityToBranch','CanvasModel');
 				
 			//add it to the DDM
-			var success:Object = _cv.ddm.addBranch(b);
+			if(b != null)
+				var success:Object = _cv.ddm.addBranch(b);
 			
 			//flag the model as dirty and trigger a refresh
 			_cv.stopTransitionTool();
@@ -674,6 +675,11 @@
 			if(!_cv.ddm.activities.containsKey(toAct)){
 				return new LFError(Dictionary.getValue('cv_trans_target_act_missing'),"addActivityToTransition",this);
 			}
+			
+			var branch = _cv.ddm.getBranchesForActivityUIID(toAct);
+			if(branch.target != null) {
+				return new LFError("Can't create transition between activities in different branches", "addActivityToTransition", this);
+			}
 				
 			//check there is not already a transition to or from this activity:
 			var transitionsArray:Array = _cv.ddm.transitions.values();
@@ -776,8 +782,8 @@
 		var toAct:Activity = transitionActs[1];
 		
 		var sequence:Activity = _cv.ddm.getActivityByUIID(fromAct.parentUIID);
-		var b:Branch = new Branch(_cv.ddm.newUIID(), BranchConnector.DIR_TO_END, fromAct.activityUIID, activeView.endHub.activity.activityUIID, sequence, _cv.ddm.learningDesignID);
-		
+		var b:Branch = (_cv.ddm.getBranchesForActivityUIID(sequence.activityUIID).myBranches.length > 0) ? new Branch(_cv.ddm.newUIID(), BranchConnector.DIR_TO_END, fromAct.activityUIID, activeView.endHub.activity.activityUIID, sequence, _cv.ddm.learningDesignID)
+						: null;
 		return b;
 	}