Display driver nvlddmkm stopped responding and has successfully recoveredLots of forumposts on the internet suggest it's a defect card, old drivers or too small PSU. My findings for my problem was that the fan on the video card actually had malfunctioned. So it was partly a defect card, but just the fan. Which can easily be replaced. Of you don't want to open up your case at first, you could try to check out the temperature of the GPU. I used HWiNFO32. Run it in "Sensor mode" only, and you should find the temperatures at the bottom of the status list you get. Here my 8800GT was hovering around 97 degrees C while going as high as 138 degrees C while playing before it borked.
New fan - problem fixed :)