Problems - Is it my PSU?

I've been having problems since I upgraded my PSU and RAM about two months ago. I also flashed my BIOS at the same time so I'm not sure where the problem lies.

Here's what I've got:

Athlon 64 3000
MSI K8N Neo Platinum
2x512 Corsair Value Select DDR400
ATI Radeon 9600XT
ATI TV Wonder PCI
WD 80GB EIDE
WD 160GB SATA
NEC 3500 DVD Burner

When I upgraded my PSU, I read a lot of stuff first. After reading that most people way over power there rigs and that even loaded rigs won't use more than 250-300 watts, I decided on a good quality SeaSonic S12-330.

What's now happening is that when I play games I'll get about 4-10 minutes into it and I'll freeze up. This happens every time I play Quake 4. It also freezes every time I encode a DVD with DVD Shrink.

Also, once every several days it will lock up a bunch just cruising the web or other non intensive things. Then it will be fine for a few days.

I'm fairly sure it's not a memory problem as I've run Memtest86, removed the new stick, swaped slots, etc. All timings are set to auto in BIOS. I've tried bumping my AGP voltage and my mem voltage with no luck.

I'd hate to have to trash a brand new $80 PSU, but if I have to...

Any recommendations for a quiet unit that will last through another upgrade in a year or so?

Thanks all!

hmm... i've experienced this problem once. And i was able to narrow it down to a rather unstable motherboard. Of course it will be hard to tell unless you swap it out with another. :?

I think I solved the problem.

I finally pulled the PSU out of my daughters Dell Dimension (you should have seen their faces). Noticing that it was only 250W, I almost didn't try it, but I'm glad I did.

I fired up Quake 4 and it played fine for over an hour. My daughters played their stuff for a while with no problems too.

I then ran to CompUSA and got an Antec TruePower2 480W ($50 in rebates) and all is good so far.

Thanks all!