Originally Posted by netllama
Does this problem persist if you're not using the Composite extension and the Coolbits & TripleBuffer options?
Have you verified that you're using the latest BIOS?
I did upgrade to the latest bios, it didn't help.
I just disabled Coolbits, set TripleBuffer to false, disabled AllowGLXWithComposite, added a Section "Extensions" and set Composite to "False"
I have not been able to reproduce this problem since disabling these xorg options.