MouseEvents bubble and the default itemRenderers do not swallow events.
Don't use custom renderers that swallow events.
My custom item renderer doesn't do anything to the mouseUp event. Every function it overrides calls super immediately. I don't know how this could prevent an event from bubbling. I can catch it at topLevelApplication.
Make a small test case and see if your problem exists there.
D'oh, you got me. I had tried to make my own event listener and had a name collision with List's own mouseUpHandler, so I just overrode it and called it with super. It looks like the listener for that function is toggled on and off depending on various conditions, hence the lack of feedback. Added my own event listener ( addEventListener(MouseEvent.MOUSE_UP,mouseUpHandler2,false,0,true); ) and it works fine now.