Game window minimizing, mouse locked on Ubuntu 9.04 Jaunty

[jdwisew]

I just bought the suite of games for Linux. Install ran smoothly and I began playing the game. A couple of minutes in, and the game window minimizes (i.e. so I can see my desktop, as if I'd clicked a 'restore window' at the top right of any normal window). I tried a couple of keyboard shortcuts to minimize the window to taskbar, restore the window size, close the window, start up a terminal, etc, but no set of keyboard inputs worked in or out of game. Also, mouse was frozen in the game window; sometimes I could move it in game and sometimes not, but I couldn't move the mouse to my desktop. I couldn't figure out a solution and had to do a hard restart. This has happened to me several times, each time a couple of minutes into gameplay. Any help would be appreciated.
-JD