SATA blue screen while running 3D games

I'm getting regular blue screens while running 3D games (I tried a variety of them, and they all crash except Doom3 for some reason...and no problem while just running Windows Vista). Most of the time the blue screen gives no clue as to the problem, except the last time it said the crash was in win32k.sys and dump_iaStor.sys. I presume this is a problem with the SATA driver. Perhaps a conflict between the video driver and the SATA driver?

I have AHCI turned on. Would it have been better to run the SATA drive in IDE mode. Do I really get much of a performance boost with AHCI? Also, am I correct in thinking I will have to reinstall windows to switch off AHCI? (notwithstanding the sticky topic related to this which seems to be about switching between two different drives, not switching controllers on the same drive).

I have installed the latest sound and video drivers. I only so far installed the SATA/RAID driver off the CD that came in the motherboard box.

My specs:
Motherboard: Gigabyte GA-965P-DS4 (rev. 3.3)
CPU: Intel E6600
RAM: 2x1GB Apacer 800MHz DDRII
HDD: Seagate SATA 500GB
Video: Inno3D 8800GTS 320MB
Sound: On-board Realtek ALC888
CD/DVD: ASUS 18x SATA Lightscribe DVD RW
OS: Windows Vista 32-bit

No overclocking. The default setting in the BIOS is no AHCI, but if I change it to that now Windows won't boot without a full reinstall. That was what I was trying to avoid.

As you intalled Vista with AHCI enabled, it would appear that you can disable without problem, as vista will then just not use that driver. Problem is when other way round, if install Vista with AHCI disabled, driver is not loaded, hence problem if you then enable AHCI, failure to boot.
What make/model of PSU? That is a high power system, needs good 480W or more. If you paid $40 for PSU, is not good. 3D games make video card suck more amps on 12V supply, can cause instability/crashes!

Mike