OK gone through the clips with Vdub frame by frame, and indeed the scenery skips 1 frame in 4, so it goes 1 2 4 5 6 8 9 10 12 etc if it only occurs when scenery is moving accross the screen (when turning) I would guess if it clears when turning Vsync off, it could be some problem with the GFX card trying to send frame3, but by the time its about to be displayed frame 4 gets the ok signal, and gets displayed instead. Interestingly the FPS display seems to be mainly at 74.8 when the next frame is displayed and @ 75.1 on the "good frames" but that is probably coincidence.
Vixer just to clafiry, what display are you using?
Are you using the displays "native resolution"?
are you using a good quality DVI cable?
what version Nvidia drivers?
did you uninstall and remove (with the tool) the old ATI drivers?
does this happen with AA + AF on and off?
Is your GFX card overclocked?
do you have your frame rate limited in game? (options misc) try limiting it to a value higher than 75. (try 100 for example)
does this happen @16bit and 32bit resolutions?
(why is this thread not in Tech Ass? its not like Scawen can make 75Hz Vsync PC's display 150fps its just not possible