I recently updated to the latest Nvidia driver (260.99, Windows 7, 64-bit) only to discover that it breaks the communication between my monitor (NEC P221w) and NEC SpectraView 2.  This results in SpecraView 2 (ver. 1.1.05)  disabling itself at every boot up and complaining it cannot communicate with the monitor.  The only solution I have found so far is to revert to a previous Nvidia driver.  I could not find any mentions of the problem on Nvidia’s site.
On a side note, the latest driver is made up of multiple components, with each require a reboot to remove.  🙁