Nvidia has announce a flaw in its latest 196.75 version Nvidia drivers
than can cause GPU burnout due to the fan speed sensing code.
Destroying your GPU is a expensive occurance.
A good solution..
I got rid of the POS on-board fan on my GF8800GT TOP when I bought it.
If your serious about keeping your GPU cool no matter what the circumstances
Get one of these...keeps my GPU around 50-60C at full load.
Even comes with stick on mini-heat-sinks for the ram chips
http://www.xbitlabs.com/articles/coolers/display/zalman-vf2000-led.html
cheers