I just wanted to state I'm having the same issue with an Nvidia card. So, I doubt this is ATI specific. I'm using OpenSUSE 10.2. The problem happens even if the screensaver is set to blank. 2.6.18.8-0.3-default Nvidia driver 9755 KDE 3.5.5 "release 45.4" I have all of the updates available from OpenSUSE's stable repository.