http://bugs.winehq.org/show_bug.cgi?id=8291
--- Comment #9 from Brian Vuyk brian@brianvuyk.com 2007-11-08 15:36:11 --- Just a note, I have found a workaround.
Keep a window open in the background. *Not* a terminal window or other window waiting for input.
By pressing alt+tab and temporarily bringing up the task-changer window, the mouse is unstuck, provided you click before releasing the keys.
This description may not be totally accurate, but it is the best I could do - you sort of have to feel it out. It really isn't ideal, but allows you to at least play the game.