White Background and Applicationswitcher

Hello community!
I’ve got a problem with my openSuSE 11.0-installation. I’ve installed the latest updates for the distribution, the ATI-driver from the ATI-repo for my Mobility Radeon x1600 and compiz-fusion.
Most of the effects work properly but if I press “Ctrl” + “Alt” and “down” I see a totaly white screen with only the borders of the windows on my desktop. I can’t see the content of my windows or the my desktops, only a whit, plane background.
Does anyone know how to fix this error? If you need some logfiles or output of commands, feel free to ask.

Thx for respondings…