First thing I had noticed is that the "Look up" three-figure double tap gesture had stopped working with my magic trackpad in OS Lion (on my iMac). No matter which of the main apps I tried this in (Mail, Safari, etc.) I wouldn't get a pop up. I finally figured out it was interfering with MenuCalendarClock which evidently has the same gesture to make the events list drop down. I quit the app and the Look Up gesture started working. In the meantime I had unchecked and rechecked every item under Point & Click in System Preferences. For whatever reason, this caused me to lose the the ability to tap, tap-and-hold to drag, and I have not been able to get it back. Every other gesture works fine. Drag still works with my Magic Mouse. I tried restarting my computer; I've tried unpairing it and repairing it - nothing has worked yet. Is there any fix, any Terminal command, etc. that might restart this gesture?