Problems with cod

Okay so I have this very annoying problem when I play either cod4/5. I got imo pretty "good" pc, atleast good enough that it should properly run both of these games. Anyways, on CoD5 I often when I have over 800x600 resolution get the game frozen, it just freezes, then some "things" dissapear (i mean the 'picture' gets clearer, like bushes go away etc.) and then it just stays here until I either boot my PC or turn it off from taskmanager whatsoever.

I've had this problem since beta, dont know what is it about, I've allready "used vacuum" (dnno the word) to clean most of powder and dust. I also ran CCleaner, checked for viruses with Avira Antivir and downloaded the newest SP. Also, I updated my drivers since I did this last time when I bought the pc like 9months ago.

Well, I figured it's just about the game, so I tried to play CoD4. It seemed to run fine with 1200x700 or something, but when I had my resolution at 1280x1240, I played only for like few mins and same happened with this game too.

It's really annoying and I'm thinking if its about the gfx card getting too hot? Can I take it back with warranty if its about gfx card? Or is there something wrong with the model maybe?


My specs:

Inno3D 8800GT 512mb
2GB ram
E6750 @ 3.4ghz

shouldnt it run just fine? people with alot worse pc's are playing it with better resolution than me ffs :$