Twittern

If you own a NVIDIA graphics card you should read the following bluepost from Datth:

"We're getting reports where users are getting intermittent low FPS after installing these drivers. It seems that it is related to the fan control included in these drivers not working correctly and is causing the video card to overheat on 3D applications. This will affect Warcraft 3, World of Warcraft and StarCraft 2 Beta. Please uninstall the drivers and revert back to the older ones."

Windows XP: NVIDIA DRIVERS 196.21 WHQL
Windows XP 64-bit: NVIDIA DRIVERS 196.21 WHQL
Windows Vista/7 32-bit: NVIDIA DRIVERS 196.21 WHQL
Windows Vista/7 64-bit: NVIDIA DRIVERS 196.21 WHQL

More information can be found on threads such as these:

- Major with new drivers with my- 9800gt not oc - NVIDIA Forums
- Problem with 196.75 driver - NVIDIA Forums"
- World of Warcraft - English (NA) Forums -> Recent In-Game Fixes - March 2010 - 3/4

As you can see, deleting the current drivers and switching to an older version is currently the best solution. If you seem to have familiar problems please report in this thread.