You have a fullscreen-function that just won’t work.
stage.displayState = StageDisplayState.FULL_SCREEN;
No matter what you try… it doesn’t seem to work out. The first thing you should check is, whether you have the Debug Player installed. And if you have, you might get a Security Error, that says, Fullscreen Mode is not allowed…
The answer is, that entering the fullscreen mode isn’t allowed through a MouseEvent.MOUSE_OVER, you should use a proper CLICK-Event.