I've got a GTX470 that freezes when it hits 60 degrees C like clockwork in this one single computer. I've got the following toys:
Intel i7 Sandy Bridge 2600k processor
Sparkle GTX470 video card
16GB CMZ8GX3M2A1866C9 RAM SERIAL 1866 MGHZ
Corsair tx 750 power supply
3 2TB hard drives
I tossed the GTX470 into a second computer and it ran Furmark just fine for over 30 minutes. In this fresh install of Windows 7 using both old or new drivers, no matter what it croaks at 60 degrees.
I used MSI Afterburner with the fan speed cranked and managed to finally get through the Win7 Performance test. Furmark was too much even with the fan cranked, but it seemed to take a few extra seconds to get to that 60C.
This feels like some kind of emergency kill setting in the BIOS. I upgraded my motherboard's BIOS to F9, but I don't see any settings for the GPU, unfortunately.
I had a feeling it was a power supply issue, so I unplugged a few hard drives. It seems that would back off the load a little bit. Maybe not.