[Marshall Plan] If you drag an item from the parent application to a child application's list, the cursor can get into the wrong state.

Steps to reproduce:
1. Compile mainApp.mxml and DragDropChild.mxml using the additional compiler argument -includes=mx.managers.systemClasses.MarshallingSupport.
2. Load mainApp.swf
3. Drag an item (like 'Holiday') from the List outside of the Panel into one of the empty Lists inside the child app that is loaded in the Panel.
4. Drag an item from the Spark or MX List to that same List drop target.

Actual Results: Notice that although the cursor is over a valid target, the cursor still has the red X symbol. Even after you release the mouse, the red x symbol remains on the cursor.

Expected Results: The cursor should have the green check when you are over a valid target. It should be a red x when you are dragging over an invalid target. It should back to normal when you release the mouse.

Workaround (if any):