I just installed the ArmA 2 demo and tried starting a server to play with a friend. When I got into the game I was looking to the left. When I moved forward, I'd move to the right. I could tell I was looking left due to the shadow. It's impossible to aim. I tried changing the keys in my config, etc., and could not get it to straighten out. What's weird is when I hit ESC to go to the menu, I'm facing the correct direction, but as soon as I get back into the game, I'm facing left again. The only thing I could find that sort of worked was using alt to look around, but as soon as I zoom in or anything, I look back to the left. The camera actually zooms in, but I'm not looking down a sight. The game is completely unplayable like this. It took two mags just to kill one of the AI teammates standing next to me. I tried completely restarting the game, and the problem was still there. I tried having my friend host the server, and I was still stuck looking left.
Edit: Fixe it by unbinding all the free look stuff. Guess my controller was messing with it.