Little help needed with Referback backend

Hello Shane

I have a little problem with the Referback backend. Sometimes I am unable to click on the drop-down menus (for example under My Toolkit, My Referback), so I am unable to reach the submenus. When I would move the mouse down for the submenus, it seems there is a little hole under the main menu which triggers the script to hide the submenu.
I tried it in Firefox, Chrome and IE 7 and after some page views the problem appears and I cannot continue to work.

Any suggestions?
Many thanks in advance!