I just built a new rig with the 3800+ Venice now at 2550 (8.5x300) and Ram at DDR510 (CPU/10) and HTT at 900 (300x3). So I went into Sandra to burn in my system to give me more headroom to overclock and to test my setup and once I hit start burn in my system just shutdown. So I turned EVERYTHING back to stock, voltage,speed, multiplier and tried to run Sandra again and it shut down again. I for some reason think my rig doesn't have enough power but I honestly am lost.
I tried for the Epsilon 700w but it was out of stock when i ordered all my parts so I went witht he 600w figuring who needs all 600w, but maybe I was wrong.
I don't know that power supply, but I sure wouldn't think 600 watts would be the problem. Sounds more like you've got something messed up in your BIOS. I know you mentioned you sent everything back to normal, but you might try clearing the BIOS completely with the jumper, then go in and select "setup defaults" or "optimized defaults" and see if it clears up the crashes.
A few pointers.
With the odmc, it can be memory picky. Most problems are cleared if the v-dimm is raised to 2.8.
Ocing the A64s takes patience. My 3200 is able to do 2.6ghz now. When I first got it, it crashed @ 2.45. Run in normal mode for a while. Join our folding@home team, for a good burn-in.