Mission Control has stopped working. Pushing the F3 button shows only open windows, but no spaces/desktops. Keyboard shortcuts (set to OPT+arrows) still work. 4-finger swipe still moves between spaces. I just did a restart, and that didn't fix anything. When doing a 4-finger swipe up, the background image doesn't shrink like it used to to show the different spaces. Also, when doing the swipe up, if I click where a desktop SHOULD be (Mail and iCal, I run in full-screen mode all of the time, so they have their own desktops) I'll go there. So it's as if Mission Control works, but just doesn't quite represent itself graphically. Lion has been working fine, up until now. Any ideas? Edit - Mission Control also does not work when clicking the Mission Control "app". Very strange.