eVGA's overclock tool Precision has been updated to revision 1.9.1 - it contains a small fix for the latest ForceWare drivers:
EVGA Precision v1.9.1 (01-21-2010)
- Added workaround for overclocking bug of ForceWare 196.21. Please take a note that the workaround is applied only to 196.00 - 196.21 driver versions range in order to ensure compatibility with future fixed NVIDIA drivers.