DropDown behind AdBanner

The DropDown menu on the main page is appearing behind the Ad Banner. Is this a common problem? Can I do anything to fix it?

Originally posted by TechnoTone
The DropDown menu on the main page is appearing behind the Ad Banner. Is this a common problem? Can I do anything to fix it?

Still no solution to it (has been reported many times already, but we lack a good PHP developer to fix this)