It did it again...best I can tell 20(ish) mins into being idle (only does it when idle). Screensaver is set to OFF. Power management is OFF in Knoppix and in the machines bios.

This time the screen slid down half way...putting the top on the screen in the bottom half and the bottom part of the screen on the top half... strange.

The mouse was still usable...sound still worked....I just powered down and rebooted.

Any ideas folks?