It would help to know 1) *which* nVidia
drivers are you referring to (the WDDM 1.1 pre release for Windows 7 or the Windows Vista drivers) and 2) Which version of Windows 7 you're running as well (although I am going t assume 7048 since that is in your profile, but some have not updated profile to match new builds).
Latest can be up to 3 different drivers at any given moment, considering that you have WDDM drivers for Windows 7, nVidia releases for non mobile GPUs and nVidia releases for mobile GPUs....
FWIW - I have build 7068 (x86 on my laptop and x86-64 on my desktop) and the desktop *likes* the 181.71 WDDM 1.1 pre-release drivers....
And so do my pair of GTX260s....
Also, I *highly* recommend that you grab a copy of
Guru3D - Driver Sweeper and install it - it works in Safe Mode and removes only waht you tell it to. Works with nVidia, ATI, RealTek.....