Middle button is not assigned to two-finger tap by default

[Munchkinguy]

Ubuntu 12.04

As described here (http://askubuntu.com/questions/126920/how-to-assign-middle-mouse-click-to-two-finger-tap) the middle button is not assigned to the two-finger tap on a multitouch pad by default. The method for correcting this is user-unfriendly.