It seems that my display corruption issues are quite spread.
I found a lot of threads in the nvidia.com forum with users with the same issue. It seems to only affect people with out-of-the-house overclocked cards, like the EVGA Geforce 7900 GT KO, which I posses. Also it just seems to happen with the 7900 GT series. Some users wrote now that lowering the GPU and memory clock a little bit solves this issue.
I sadly can’t try this because nTune will hang my system and it’s the only software which could currently do this under Vista x64. CRAP!
Waiting now for a different solution….
Here a video from a user which has the same problems: http://www.youtube.com/watch?v=ZDYlMPe2X1Y
And here a nice thread over at Nvidia about this issue: http://forums.nvidia.com/index.php?showtopic=42207