Three-finger trackpad gesture on Mission Control and Expose not working in my Mac Pro The trackpad gesture to call Mission Control or Expose with three-fingers does sometimes not work for some reasons. It works when I use four-fingers, and it functions as usual whenever I open my System Preferences and reset the Mission Control and Expose section to use three-fingers gesture (instead of four-fingers). However, it's set to three-fingers at first, and it's just that I first disable it and then enable it again...

The symptom occurs whenever I restart my Mac, so it's nothing but tedious to bother to open my System Preferences to check off and then on to the Mission Control and Expose checkboxes. As I said, when I reset the setting, it works as usual.

My trackpad is Apple's Bluetooth trackpad, and my Mac Pro is late-2013 machine. I also use mid-2012 MacBook Pro with Retina display, and while it might occur on the machine at times (maybe only a couple of times per 1,000 sessions), I have not had such issues almost usually.

Is there anything that I should investigate further? PRAM and SMC didn't resolve the issue... I'm curious to know why it occurs whenever I restart my Mac, and how to solve the issue.

I use the latest version of Mavericks.
This sometimes happens to me, where the 3-finger macro stops working. Seems like OSX just bugs out. My hotfix right now is to open the command line and run killall Dock. Seems to work fine for resetting it and getting it working again.