I can get to full screen without any problems. The problem is that when I go into Full Screen the game freezes. In windowed mode, I get to the main menu, the framerate is 2fps. Once I get to any other part of the main menu (Graphics, Movies etc) The game runs fine again. Once I start the game, it too works perfectly at about 50fps. But, if I switch to windowed mode, the game freezes. I've tried making the game run at 1440x900 and lowering the resolution to the same but the game still freezes. I can't think of anything that would cause this now.
EDIT: This came up after I minimized the game and uh..."un-minimized" it.