General Troubleshooting - System Hang/Sound Loop

[Javey93]

Hi guys. Basically, my issue is a sound loop and system hang when playing Battlefield: BC2. More recently it's happened in CallOfDuty4 too, and i don't know of any common factors between those two games.I've followed a crap load of support from EA's help site, but none have that has worked. This leads me to beleive it's a hardware issue inside my rig. What are the first things to jump out at you? Please list them and tell me how i should diagnose if this is the case. Just to let you know, the issue only appeared when i;

1. Upgraded from E7400 to Q6600
2. Flashed BIOS to most recent version

If it is possible that the BIOS is the cause of the problem, does anybody know how to roll back the chip? As EX Flash doesn't give me the chance to accept/decline my outdated ROM file... T_T

I know you're not some tech support forum, but i've had first class assitance from you before and i didn't want to go anywhere else. Besides, if i need anything, link me to the Overclockers site! Thanks guys, much appreciated.

 

[Puppetmaster]

Whats the full spec of your system?

 

[Javey93]

I WAS going to send you my dxdiag, but i noticed it's quite large.

Q6600 @ 3.6Ghz - Stable on Prime95 for 24 hours.
XFX5870 @ default - around 50% of the people with the BC2 problem have these...
OCZ DDR2 Platinum 1066Mhz
P5Q Deluxe
7 64 bit
900W supply
ADI® AD2000B 8-channel High Definition Audio - inbuilt...