(still rough translation)
I have a Sony Vaio vgn-aw180fu with Ubuntu 12.04 Precise Pangolin. Everything was fine, until I opened a terminal to install cairo updates that the Update Center wouldn't let me install stating that those were untrusted packages.
Upon installing the updates, the screen froze; I waited and nothing happended, so I forced a shutdown.
Then I installed Google Earth, which previously the Software Center couldn't [sic] install, and the screen froze again. Again I waited but it didn't change. I forced shutdown once again, and then Ubuntu would not start. From grub I entered to "repair ubuntu", and selected "repair damaged packages" and could log in again.
The laptop touchpad no longer had the normal functions, one being that the pointer moves too fast; this is the least important, and what bothers me most is that the double tap (double click) to open or move windows does not work anymore.
This has happened to me before and I had to uninstall and install it all over again. I read that there are many problems with the touchpad for notebooks with Ubuntu. It's a good system that has made me much satisfied and comfortable but the touchpad problems and not knowing how to correct them make it very uncomfortable
I might try try with another Linux distribution. Greetings.
[In Spanish below]
If yours is simply a configuration problem, here's what you could do:
First, press the [Super] key (the one that usually comes with a Windows logo) and start typing the words System Configuration
Click on the icon and then look for Mouse and touchpad under Hardware. You'll be presented with two tabs, the second of which corresponds to the touchpad settings:
Adjust speed as necessary and make sure "Activate mouse clicking with the touchpad" (Actually, I don't know the exact phrase in English, but it must be something like that).
Oprimí la tecla [Súper] (la tecla de Windows) y comenzá a escribir la palabra "Configuración".
Hacé clic en el icono de Configuración del sistema. Eso abrirá el panel de configuraciones.
Seleccioná Ratón y touchpad bajo el lema "Hardware".
Cambiate a la pestaña Touchpad del programa de configuración de ratón y touchpad, y ajustá la "Velocidad" hasta que esté a tu gusto. Asegurate que está seleccionada la opción "Activar pulsaciones del ratón con el touchpad".
Suerte.