Been having a recurring problem after minimizing the game for weeks now.
Basically, I'll alt+enter and go to windowed mode, usually when the server changes maps and the mouse will stop functioning. If I manage to alt+tab to something else my mouse will hover around the center of the screen, move a bit and then re-center. Basically the effect is that it vibrates. It's as if Windows thinks I'm still playing the game, except I'm not. Generally this problem is only fixed after a mapvote or something. Meanwhile, I can't really do jack ****. Can't even refocus the game.
mine does that a fair bit after minimising or an msn pop up causes it to falter, usually in_restart sorts it out in the console, on the odd occassion that will fail because the mouse is stil focused on the other pop up or application so i have to close that ie msn chat or whatever caused it to get it back to focusing on QL