Asus P5Q Deluxe Problem

I have a problem, and i believe it to be the m/board that's playing up. Let me explain.

I built my rig back in November with the following components;
Asus P5Q Deluxe Board
E8500 3.16Ghz CPU
4Gb Corsair Dominator 1066Mhz Ram
HD4870 1Gb Sapphire GPU
Freezer Pro 7 Cooling
Thermaltake Shark Case

All was good and everything running fine, overclocked the CPU and the GPU, again all working fine. All on Vista 64Bit

Now within the last two months or so i started getting problems while gaming, but only one particular game...CoD4...

I can play Crysis fine i can play CoD5 fine. But CoD4 will randomly crash (when i say crash i mean the whole system freezes and i have to do a manual reboot and get no error messages on boot or anything to go by).

Now i've tried everything i can think of; Updating all my drivers, rolling back drivers, memory tests, scans, everything. Today the game has even crashed in Safe Mode, which is just crazy.

Right so i got talking to some mates online, and he said his neighbour has had the exact same problem with his board and eventually he got a new board, and now has no problems what so ever...guess his m/board...Asus P5Q Deluxe.

Now i've gone to update the BIOS but the update utility on Asus' website doesn't like Vista 64bit (yes i downloaded the right one but still get a compatibility error) but i think this is going to be my next best thing to do right? :shrug:

Please help

Edit:

This is the error i get when i try using the BIOS Utility from ASUS' website;
http://img3.imageshack.us/img3/1034/errormlb.jpg

I had a P5Q Deluxe ages ago and it was a great board. I would lower your overclock and see if it becomes stable. That error message looks like your trying to run a 32-bit exe on a 64-bit platform.

I never update the BIOS like that, I always download the .bin/.rom file, copy it to a disk and boot from it

Well i've managed to update the BIOS and it seems to be working better now, but did have some problems on boot, so we'll see how that goes...

I have noticed however that when i use the supplied disc and click motherboard information my 1066Mhz RAM is listed at 667Mhz for current speed, is this just because it's idle? :shrug:

As far as I know ram doesnt change speed if its idling, you've probably got a low divider set in the bios

Anyone got any idea on this one? Altering the RAM settings?

Sounds like since the BIOS flash you are running 333 FSB and 1:1 divider giving 667 MHz ram. Go into BIOS and set your overclock again, as when you update a BIOS it resets all settings to defaults again.

Crashed again today...

>Not happy<

Any ideas?

Set PCI express frequency to 105 mhz and raise SB voltage 1 notch?