MouseUpEvent stops working while Dragging MovieClip

Question

There is a mouseUpEvent listener attached to the stage in the main class, while dragging the movieClip the mouseUpEvent doesnot trigger the handler and the movieClip gets sticks to the mouse. While the item is being dragged and the mouse is moved away from the movieClip i.e somewhere not on the item but on the stage the mouseUp is detected.
Edit: Here is the scenario I am using a static (Singleton) class as a movieClip as a "DragManager". Whenever a movieClip has to be dragged it is passed to the DragManager and is added as a child, when a mouseUp from stage is detected another static function of dragManager is called to stop the drag and put the movieClip on the appropriate layer. Here is the static function in the DragManager which is called on MouseDown from variouslayers.
public static function startDragMethod(item:Item):void
instance.addChild(item); //This is the instance of the DragManager
var boundArea:Rectangle = new Rectangle(0,0,610,760);
item.startDrag(false,boundArea);
In the constructor of the main class I add the eventHandler for the MouseUpEvent
this.addEventListener(MouseEvent.MOUSE_UP,stageMou seUpHandler);
The MouseUpHandler in the main class
private function stageMouseUpHandler(event:MouseEvent):void
DragManager.itemMouseUpHandler(event);
If there is something wrong with technique please guide me, my goal is to implement drag drop between various layers and with as less coupling as possible.

Answer 1

1.  by "main" class do you mean document class?
2.  does a trace() in stageMouseUpHandler fail to execute with that mouseup event?