Hey this a late reply, but in case any one else runs into this issue....

I just started the game and had this problem. I was getting 838fps in fullscreen, and the game just didn't knknow how to handle it, so walking broke. When I play in windowed mode, it locks to 60fps and movement works fine.

I imagine you could get fullscreen working by using either your video card software or a 3rd party program like Riva Tuner or special K to lock your FPS to 60.

Eidt: after some additional testing, the game can handle 120fps and 240fps just fine. Not going to test further since I don't see much point in going over 240 fps. Just make sure you cap it at something reasonable, that should be all that matters.