GOBLEGOBLE

So I've come across an odd problem. when I play the game my crosshair is constantly, slowly moving upwards. It just started happening last night, and wasn't there for the previous hours I played renegade X nights before. It only happens in game, not at any menu screens. I've unplugged my mouse, while in game, to make sure its not the mouse malfunctioning, and it still happens. I've also uninstalled and reinstalled the game with no success. any ideas on this? am I missing something? THANKS!