Ubuntu 14.04.1 LTS on a Macbook Air. Using exactly two fingers on the trackpad, then double tapping with either third finger brings up the same menu as Alt-Tab does.
Is it possible to turn off this shortcut?
Apparently I was triggering 3 finger tap.
https://wiki.ubuntu.com/Multitouch#Supported_Gestures
The solution as posted by rupert here was to run:
synclient ClickFinger3=0
synclient TapButton3=0
If this does the trick (or a variance of 0 , 1 , 2, 3 , ) you can add it to startup.
Specifically for me (Macbook Air 3,1 or 3,2), the following worked:
synclient ClickFinger3=0
synclient TapButton3=1
TapButton3
to 1 to disable the gesture.