Windows 7: Input Lag in All Games with Vsync On

I have an NVIDIA GeForce 9800 GT. On XP, I could enable Vsync and disable frame buffering to cure mouse and controller delay (lag). On Vista and 7, turning on Vsync causes almost a second of input lag no matter what game I'm playing. I'm mostly into FPS games, so this makes it hard to aim.

I can confirm this but only in one game. For now. In Far Cry 2 theres a fps drop by 50% with the Vsync on, problem that was not present in Vista Ultimate 64. If turned off, game runs smoothly at Ultra High settings.

Cheers.