The problem is with the effects added lately, namely "blur". KDE blames Intel for their bad drivers, which I cannot verify, only work-around...
Disable "Blur" under Settings > Desktop Effects > All Effects and
Disable "Direct Rendering" under Settings > Dektop Effects > Extended.
May change the rendering engine if
Lemme see if I can find that thread where this has been discussed......http://www.pclinuxos.com/forum/index.php/topic,78662.0.html
That should help. I'm using e.g. "really" wobbly windows and it works with no issues. Love it
In PCLOS 2009.1 you won't have the current effects, so no problem. In Kanotix, maybe some effects that might cause trouble have been disabled.
Wait for the 2.6.38 Kernel to hit the repos, the we may try again if all is working. AFAIK Intel updated the drivers.