[flexcoders] 2.0.1 ListBase.as error

[Shannon Hicks]

I have a datagrid with a change event handler. When a user clicks on an 
item, it's supposed to take them to another state. I keep getting a 
"Cannot access a property or method of a null object reference" error. 
While this is not uncommon for me, the error actually occurs on line 
7029 of ListBase.as:

    private function mouseIsUp():void
    {
        systemManager.removeEventListener(MouseEvent.MOUSE_UP, 
mouseUpHandler, true);
        stage.removeEventListener(Event.MOUSE_LEAVE, mouseLeaveHandler);

        if (!dragEnabled && dragScrollingInterval != 0)
        {
            clearInterval(dragScrollingInterval);
            dragScrollingInterval = 0;
        }
    }

The line with the error is "stage.removeEventListener(Event.MOUSE_LEAVE, 
mouseLeaveHandler);"

Everything worked great before the 2.0.1 update. If I ignore the error, 
everything continues as expected. Any ideas?

Shan