Cacher is the code snippet organizer for pro developers

Download this (currently newest package is 1.3): http://www.dahetral.com/public-download

(Really say thank you to these people who wrote this driver, God bless them!)

Untar and copy (as root) the psmouse-alps-X.x folder to your /usr/src directory (now X.x = 1.3).

Once copied just run these commands :

$ sudo dkms add psmouse/alps-X.x
$ sudo dkms autoinstall
$ sudo rmmod psmouse && sudo modprobe psmouse

Now you'll find the TouchPad tab under mouse settings and you can enable scrolling and so.. just because now is considered a touchpad and not a PS wheel mouse.

NOTE: if a new driver comes just the new one in /usr/source and repeat the procedure.
For cleaniniess remove the old one with :

$ sudo dkms remove psmouse/alps-X.x --all

Where X.x is the number of the old version to remove from dkms.
Then you can also remove the relative folder.

---------------------------------------------------------
Source : http://ubuntuforums.org/showthread.php?t=2043445