I have a Mighty Mouse with the two side buttons. I set up Mission Control to launch when I clicked either one, and everything worked perfectly. Then one day it stopped working. So I thought to change the batteries in the mouse, but that didn't fix it. So I did some testing. If I assign another comman to the side buttons, like Dashboard, it works fine. So the mouse buttons are physically ok. If I press Ctrl + up arrow, Mission Control launches, so nothing wrong with that aspect of it. I can't figure what might have happened. Also worth mentioning, yesterday I had Launch Pad assigned to Ctrl + down arrow. It worked great for a while. Then I installed a System Preferences app called LaunchPad Control, which allows you to control which apps you see in the LaunchPad, without deleting the apps. I think, not certain, that it was after that install that the shortcut stopped working. Thought launching LaunchPad from Apps works just fine. I checked that I don't have any conflicting shortcuts assigned to the same keys, and from what I can tell, I do not. Any ideas???