Mouse freezes game

[Hitmanx]

Hello, yes i know there is a topic called mouse lag, but it was unsolved and it's really bugging me! the game runs fine on my computer standing there and not touching the mouse it's smooth as. The second i touch the mouse it pretty much freezes until i let go of the mouse.

I've tried getting new graphics drivers, i've tried turning the graphics down to as low as they get, nothing works!

I've managed to get to the spiderpart but it's just really getting on my nerves now, and it'll be hard to fight enemies when it lags all the time.

This is the only game that does this, i can play crysis (all on low) and there is no mouse lag like this, orange box is fine, cod4, MOH:A So it's not my computer..

HELP PLEASE!!!