This is the key: ( after hours and test… )
http://help.adobe.com/en_US/flex/using/WS2db454920e96a9e51e63e3d11c0bf68641-7ff0.html
http://help.adobe.com/en_US/flex/using/WS2db454920e96a9e51e63e3d11c0bf69084-7de0.html
so:
override protected function updateDisplayList( unscaledWidth:Number, unscaledHeight:Number ):void
{
super.updateDisplayList( unscaledWidth, unscaledHeight );
var ScreenPos:Point = new Point( this.x, this.y );
ScreenPos = this.contentToGlobal( ScreenPos );
if( MainView ) MainView.setSize( ScreenPos.x, ScreenPos.y, unscaledWidth,
unscaledHeight );
}
I think this is finally the right way ( or not, what about skins, eh ??? 
)
Flex is another world…
the result are:
