Trackpad gestures stop working From time to time, my Magic Trackpad gestures will stop working. I can restart to bring them back, but this is pretty disruptive.

Is there a process I can kill to bring them back?

(I've tried turning off the Magic Trackpad; unfortunately, it doesn't fix the problem.)
In 10.8, running killall Dock seems to bring back trackpad gestures.

When a reboot didn't fix this, I went to System Preferences → Trackpad → More Gestures and changed


Mission Control to ‘Swipe up with three fingers’, and
App Exposé to ‘Swipe down with three fingers’.


Those gestures now worked with 3 fingers. Then I changed it back to ‘Swipe up/down with four fingers’ on both and they started working again using the four-finger gestures.