After upgrading from Ubuntu 11.04 to 12.04 the h-scrolling two-finger quester on my Magic Trackpad stopped working, despite being enabled in the ‘mouse and touchpad’ settings dialogue.
A little digging and guessing led me to:
$ xinput list
$ xinput list-props 'Apple Wireless Trackpad'
The output of which included:
Synaptics Two-Finger Scrolling (377): 1, 0
I had already found that the
Synaptics Scrolling Distance property’s value was in the order ‘vertical, horizontal’, so guessed:
$ xinput --set-prop 'Apple Wireless Trackpad' 'Synaptics Two-Finger Scrolling' 1, 1
And it worked! :D