Problem menu

Hi,
All of a sudden the boxes under the mainmenu don't want to stay as soon as I point my curser on it.
As a result I can not navigate or choose my submenus ?
Any suggestions ?
Thanks

Hi

Please show me your site.

I turned off Css Override and the menu started back to work (?)

Hi

Ok. So problem must have been in a code wirtten for override. It's empty as default.