Is this BSOD an 8800gt or motherboard problem?

I just built a new PC and used an 8800gt that I've had for about 2 months. I've got everything running correctly now except for a BSOD that keeps popping up when I play WoW or AoC for a while. It's happened with three different driver versions (175.19, 177.79, 177.83) but seems to have become less frequent while using 175.19. I was able to play AoC for about an hour or so before anything happened today.

The BSOD cites nvlddmkm.sys as the problem but nothing I've done has solved it. I've tried uninstalling the drivers and reinstalling after cleaning up with Driver Sweeper but that hasn't helped. I heard that underclocking my memory could help but dropping it to 667mhz didn't do anything. I've tried using MemTest but it didn't return any errors after an hour. I'm currently running it again. I'm using the latest BIOS and chipset drivers on my motherboard and the only overclocking in my system is my video card which was factory overclocked. My system is:

Intel e8400 @ 3.0ghz
ASUS P5N-D nVidia 750i SLI motherboard
Zotac 8800gt 512mb
4gb (4x1gb) Patriot Extreme Performance 800mhz
Raidmax 500w PSU
320gb hard drive
Windows Vista 64 bit

Any help would be greatly appreciated.

this happened to my neighbors 8800gt he called xfx they said to reinstalll vista and if it didnt work just send the card in for a replacement.

Do you think my PSU isn't powerful enough? I used it in my previous system for about 2 months and it worked perfectly. Although buying a new PSU would give me a chance to try out SLI or maybe a higher end video card in a few months.

I just read a couple forums saying that it could be overheating of the north bridge. I have a fan I can install on it so I'll try that and if it doesn't work I may have to reinstall vista. I don't think it's a video card problem since it worked fine for 2 months.

Ok, now I'm beginning to think it just may be a PSU problem as suggested. I just tried to restart my computer and it went through the motions, but instead of restarting it just shut down. Is there anything other than a PSU problem that could cause this?

My PSU came with my Raidmax Smilodon case so it might just be a piece of crap.

So all signs point towards a PSU fault? If this is the case then I'll order a new one when I get paid. Does this one look good?

http://www.newegg.com/Product/Prod [...] 6817139005

EDIT: would replacing the PSU fix my issue with shutting down instead of restarting?

yes that PSU is foxy, but you can get a slightly cheaper one if you want.
@IH8U
his card is two months old so the the HS on it should work great.

GET THIS ONE^^^^^

http://www.newegg.com/Product/Prod [...] 6817171025

Try this one instead. It has enough juice to power more than what you have by far, and is quite a bit cheaper. + I've had more luck with coolermaster products over corsair.

I just restarted my computer and got an error message saying:

H/W Monitor Status Abnormality

I looked it up and it's most likely a (surprise!) power supply issue. I get my paycheck tomorrow so I'll look into ordering a new PSU soon. I'd like to be able to upgrade to either dual 8800gt SLI or a high end card (nVidia gtx 260 or Radeon HD4870) during the next few months. What wattage should I look for?