mouse_wheel event doesn't fire on flash player

programming flash
1

I’m using Flash CS5, flash player ver WIN 10.1.53.64 and PC with win7. I pasted code below to new fla file, compile it and it doesn’t work. I did some research and found out that there is some issues using mac, or when publish in browser (wmode must be set to window not transparent) but have no clue why code simple as that doesn’t work. Just nothing happening.
I tried clicked on stage before using mouse_wheel to be sure that it has focus (which is needless in swf as far as I know) - still no result. Did I miss sth? Any ideas?

here is the code:

import flash.events.Event;
import flash.events.MouseEvent;

addEventListener(MouseEvent.MOUSE_WHEEL, mouseWheelHandler);
function mouseWheelHandler(e:MouseEvent){
	trace("delta: "+e.delta);
}