Re: downclocked ROM on EVGA GTX260 SSC 55nm (-1258-)
First I want to comment, your BSODs probably means the computer is getting hosed by RAM or CPU clocks/voltage. I never got BSOD from the video card problem, only freezes (and the music/sound effects kept going) or CTD (crash to desktop) and massive artifacts. Generally I could recover with ctrl-alt-del and kill the game. Are you overclocking the CPU or RAM? If you've downclocked the card that far, it's probably not the video card. Straighten out your CPU/RAM overclock Prime95 64-bit torture + IntelBurnTest at the same time, or try stock CPU/RAM speeds with slight over-voltage to isolate any video card issues.
I've only really played TF2, FC2 and a couple lesser games. FC2 seems very good at triggering this problem (5-15 minutes). TF2 no problems ever. The idle temp is 45-55c depending on whether the card clocks down or is stuck at 3D game speeds at the desktop. Under gaming load, it runs 68-78c or so. Under Furmark/OCCT3.0, it'll max out the fan at 85-86c. Benchmarks and stress tests run fine here too. The card wasn't too hot, it just couldn't go that fast.
Here was my clue -- adding just a few MHz to shader clock provided near instant freezes. Adding just a few MHz to core clock gave more artifacts. Adding a few MHz to memory didn't seem to do anything bad. So, core/shader were too high from the factory, especially shader.
I see your PSU is 550W. When I used the OCCT 3.0 PSU test, I measured 565W from the wall... (about 470W inside the computer). Hopefully your PSU is a good 550W one.