crashing problems with new 1950 pro

[Adrenalin]

I have recently bought and installed a Powercolor 1950 pro 512mb AGP graphics card and i am experiencing crashes in games like STALKER and Oblivion but not in games like Battlefield 2142 and FIFA 08. STALKER and oblivion will crash no matter what the video settings are but FIFA and BF2142 can run on high and medium/high respectively. This is a very frustrating problem because when i first got my computer it ran both games fine on a low setting with a Galaxy 6600 256mb AGP card and 430W PSU.
My AGP PC:
Pentium 4 640 3.2 ghz
ASUS p5s-800-vm mobo
200gb HDD
600W PSU
Powercolor 1950 pro 512mb AGP

[Ayman]

Do you have the latest video drivers for your card?
If not then get them from: http://ati.amd.com/support/driver.html

[Adrenalin]

Yes i am sure i do, thanks.

[Disk_Contented]

Latest driver is not allways the best. Try an earlier version.

[Kevin_gibson]

Try as disk_contented said, or have you tried to update the BIOS on your motherboard? This could be a good suggestion as you've replaced the card and PSU by the looks of it.

[Adrenalin]

any suggestions on which driver version i should try? also, how should i go about updating the bios on my mobo and how do i check which version of bios i have? just go to the ASUS website? is there a specific version i need for agp or whatever?