The touchpad will work fine when viewing the login screen, but once logging in to GNOME and the GNOME startup sound plays, the touchpad stops working. The touchpad stops working. So do the buttons.

The easy way to get this fixed is to open a terminal (or hit CTRL+ALT+F1 in order to get a login prompt), and then once logged in, run the following command:

 

gconftool-2 --set --type boolean /desktop/gnome/peripherals/touchpad/touchpad_enabled true

After that, the touchpad should work.