Tried that and I was stuck at 30fps again grrr
actually no, when I turned vsync on I was stuck at 30fps, I turned it on to try and cure the jerkiness but nope. with it off and limited to 60fps character movement is fine but moving the mouse is jerky.
Is it stuttering? Or just not smooth? Have you got any mods?
What about running it windowed at that res? Nvidia control panel any settings set?