System shutting down mid-game

I bought a few new pc parts a few weeks ago for the first time in a few years and have been having it just quit (power shuts off) in the middle of intensive gaming. My second question is this system isn't able to max out the new Call of Duty, not even on a lower resolution like 1280x1024. I sometimes get down to the 20fps and stuttering.

AMD Phenom II X3 720 (not black edition got screwed)
GA-MA790x-DS4
3GB DDR2 (one stick 2gb 800) (other 1gb 400)
ATI HD4850 512mb Crossfire

Right now my solution (which isn't really working) is two PSUs. One is a general 550w that I don't think has the power in it's old age (2-3 years got it from my roommate) and the other is a 350w that I've tried powering both video cards on the 350, just one, just the hdd and two fans, nothing seems to keep it stable.

Here are the stats on the back of the PSU, could this be a different problem, a bottleneck?

CODEGEN 500X
(+3.3v&+5v=235W Max;+12v1 & +12v2=320W Max ALL OUTPUT IS EXTENDED TO 550W)

Rosewill RV350-2

Here some pics for fun:

CPU never goes over 40c, is usually around 29c idle and 36c when OC'd to 3.3ghz

The most I've seen it climb was 70c under some intense singleplayer Prototype and multiplayer Shattered Horizon I've used GPU-Z logs to show the temps were sometimes around 50-60c on the GPU during shutdown. I've seen it sometimes go to 70c and still be fine and othertimes shutdown.

Then again I've also forgot to load a fan speed profile on startup and the GPU has seen 80c no problem.

Almost certainly a power issue, i plugged in your specs and it spit out 356 watts with 0% capacitor aging, most of the power a modern system uses comes from the 12 volt rail, get a good quality PSU asap because yours is incapable of providing anywhere near its rated power.
http://extreme.outervision.com/PSUEngine

Facts about 12v rails

I'll be honest when I first saw the price I cringed a bit. And while I would love to have that setup (Since i'm running without a case now and cords look bad) I just can't do 75 upfront.

(In college living off debt with a work paycheck that feels like every other month)

Any suggestions in the 40-50 dollar range? I won't be upgrading ever besides replacing one stick of ddr2 with a high capacity one. The only power drains besides whats posted are the 1 fan (one just broke) and the three usb devices (keyboard, mouse, camera (used a mic)) No burner or anything fancy.

How much power does everyone think it will take to power this rig? If he were only using a single 4850, no problem. Unsure if this will push 2 of them though, but this is what I'm running in my rig right now.

http://www.tigerdirect.com/applica [...] &CatId=106

38 amps on the 12v+ rail, and 50 bucks, but again, I don't know if it will push 2 4850's......

I doubt you will be dissapointed, OCZ is good stuff. To be honest, the one you ordered if it's the same as I looked at, is probably a better unit than what I suggested. I just knew you said 50 bucks would be preferable.