No, the problem occurs only while gaming. Blur has the problem as well (GTA4 and Blur are the only games I have installed so far)
I would consider "weird shapes appearing" a good description. The shapes are all black, only appear for a very short length of time and there are many on the screen at once. After a while, the computer crashes. Also, I use my TV as a temporary monitor...could that be the problem?
Thanks for the quick reply.