Videocard problem?

I have a strange problem. Every time I play UrU TPOTS (with many added ages) I get artifacts in the Nexus and the fan of my graphics card starts spinning like crazy. In most ages I get stretched geometry and after a while artifacts and even sometimes bluescreens.
The strange thing is... it only happens in UrU. No problems whatsoever when playing Tomb Raider Anniversary. The fan doesn't even accelerate.
I have had this problem for a few months now. Cleaning the inside of my pc and all fans didn't help. Either something is broke (I have a Radeon X1900XT) or somehow UrU messes something up.
Any ideas?
Thnx
The strange thing is... it only happens in UrU. No problems whatsoever when playing Tomb Raider Anniversary. The fan doesn't even accelerate.
I have had this problem for a few months now. Cleaning the inside of my pc and all fans didn't help. Either something is broke (I have a Radeon X1900XT) or somehow UrU messes something up.
Any ideas?
Thnx