Comment 49 for bug 315882

To be more acurate, on my U100 the mouse was unusable after a few seconds, cursor moved but click has no effect. Removing the psmouse module at startup solved this issue.

So I put only the following command (and not the other one which reloads the unwished module) in /etc/rc.local :
/sbin/modprobe -r psmouse

The built-in trackpad and buttons doesn't work anymore but the external USB mouse is working fine.

This is the only fix that worked for me (and it worked in both distribution 9.04 and 9.10)

This should probably be reported as a different bug, but I feel a little lazy after a couple of hours working on it.