There are many reports from customers on the latest 196.75 WHQL drivers issued by NVIDIA on 2nd Mar 2010. They are having fan speed issues with this latest drivers for their graphics cards. These drivers are causing the fan controller to behave erratically, making the fans to slow down or in some cases to stop completely thus overheating your graphics card and damaging them. So gamers and other users who have recently installed these latest drivers, better watch out and rollback your drivers to the earlier ver.
NVIDIA has also issued this warning officially on their site and have temporarily withdrawn 196.75 drivers from their site
If you have already installed this, NVIDIA has also provided the method to rollback to your previous drivers, follow these instructions -
Its highly recommended to rollback to earlier version, if you have installed this driver.