RAM or Video Card

When I boot up Bioshock at the save point I'm at it locks up my computer within 2-3 seconds of loading.

When I boot up World of Warcraft my computer never locks up.

Crysis, UT3, and other new games are locking up my pc too but not as fast as Bioshock. Does this sound like a RAM problem or a video card problem?

Also I built this PC myself so how do I make sure my RAM is configured right? I've heard things about RAM timing or something.

 

What kind of video card, and how much RAM? And while we're at it, other specs as well, please?

 

NVIDIA GeForce 8800GT Superclocked 950mhz
Intel Core 2 Quad Q600 2.40ghz
Corsair 520w PSU
Creative Soundblaster Audigy SE
4GB G-Skill RAM (tested w/ memtest86 v 1.70)
Intel BLKD975XBX2KR LGA 775 Intel 975X ATX Intel Motherboard
ATX Mid Tower case 2 fans
Windows XP Pro SP2

I know the card isn't overheating.

 

Are you sure it isn't the "Superclocked 950mhz" video card? HAve you backed off the overclocking a bit to see if that helps?

 

I agree with yargwel back of on the video card overclock,update video card drivers.

Run the latest 3DMARK on loop to see if you can get through it ok and run memtest,both can be downloaded from majorgeeks,also run toast which will stress your cpu to see if you can get it to lock up.

http://www.majorgeeks.com/Toast_d867.html
http://www.majorgeeks.com/download.php?det=4935
http://www.majorgeeks.com/MemTest_d350.html