The Collatz admin is recommending a fall back to version 196.21 but i found this in a Collatz thread from Zydor:

Anyone using the 196.75 WHQL driver should roll back to 196.21 WHQL to avoid issues. NVidia have released a statement acknowledging the problem, withdrawn the 196.75 WHQL driver from its Site, and recommend rolling back to 196.21 WHQL (However see below).

196.75 Withdrawn by NVidia

However, 196.21 has a bug stopping GPU overclocking. I personally rolled back to 196.34 which although formally a Beta driver, only has the GPU overclock bug fix as the difference with the bugged 196.21 WHQL

Regards
Zy