Comment 17 for bug 308191

(In reply to comment #8)
> (In reply to comment #7)
> > I have a T61 and it's happening for me too, so this doesn't just affect the
> > Dell minis.
> >
>
[...]
> For this reason I was wondering if quirks could be added for different
> touchpads (when no general solution can be found).
>
> What do you think?
>

I recognize this problem from some time ago. Have you tried applying the ubuntu patches to see if the problem goes away? (apt-get source xserver-xorg-input-synaptics, then look in debian/patches.) There might even be additional patches available at ubuntuforums for this. I am particularly thinking of the patches that disable movement when more than one finger is or recently was in contact with the touchpad.