Problem with dhtml drop down menu and a flash file

The position of a DHTML pop up menu is just above a flash animation ;
When the mouse cursor is placed over the pop menu and it drops down over the flash file area , the collapsed menu is covered by the flash.

as far as I can remember I had the same trouble 3 years ago but could not find a solution rather than changing all the lay out ;
is there a way to solve this problem ?

cheers