Now that I have established that KDE is not the source of my occasional distorted Xorg display I noticed several things in the Xorg.0.log: (Windowmaker has the problem too)
(ww) xf86AcquireGART: AGPIOC ACQUIRE failed (inappropriate ioctl for device) and (ww) GARTinit: AGPIOC_INFO failed (inappropriate ioctl for device) I don't know what these warnings mean or if they are related to me problem but I just noticed them. Sincerely, Rob -- "Emancipate yourself from mental slavery, none but ourselves can free our minds" Bob Marley, Redemption Song