Enabling the touchpad vertical scrolling for Sony Vaio on Ubuntu

For some strange reason the vertical scrolling is not working by default on Ubuntu 10.04. The solution to this problem is quite simple, but not so obvious.

To enable vertical scrolling for Sony Vaio F11 on Ubuntu 10.04 you will have to run the following command:

echo "options psmouse proto=imps" >> /etc/modprobe.d/psmouse.conf

The above command will set the protocol used for communication with the touchpad.