It was working on CS3. So I didn't update my photoshop for one year because of this problem. When I press "F" for full screen mode, it overlays the windows taskbar. And I need to see it because i have to check my emails, reply to msn and etc. It's very annoying problem whcih came with CS4 and still in CS5 and 5.1, too.
I think CS3's full screen mode is better can i get it back?
