I am trying to fix this IE7 bug (can be viewed in IE8 compatibility mode too) :

On hover, my CSS sub-menu appears behind other page elements below.
For example, Products sub-menu is behind the title and thumbnails.

My guess it has to do with the stacking order: tried to fix it by adding z-index and zoom properties to sub-menu UL, but it didn't solve the IE7 problem.
Everything works fine in other modern browsers (IE8, FF3, Safari, Opera, Chrome).

Any insight from CSS gurus would be appreciated.