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#11
Update: I swapped out the video card to my old 6450 and I also swapped out my ram to the OEM sticks (it's a Dell 7100), on the recommendation of a friend who suggested that voltage issues with performance RAM might be the culprit. It booted stably to Win7, I uninstalled everything ATI-related (Catalyst, drivers, etc etc) and shutdown normally.
I then swapped the 6450 back to the newer 6950 and booted the system up and installed Catalyst 12.3 clean, and everything appears to be stable at this point.
My question at this point is: can voltage issues (undervolting or overvolting) with RAM lead to corruption of graphics drivers? Dell's BIOS is pretty much locked, so I can't manually control RAM voltages, so I'm sticking with the 8GB of OEM RAM at this point until I solve this issue.
Thanks all--