Depth stupid issue

I have a movieclip on top of another movieclip. I added MouseEvent.ROLL_OVER event to the movieclip below… and when i roll over the movieclip on top which is also on the rollover of the movieclip below it does not act as rollover of the movieclip below.
It should ignore the movieclip ontop as it has no event handling. How to make it ignore it? I tried the enabled property but it does not work… also set the buttonMode to false but nothing…