After I upgraded to Kubuntu 8.10, the touchpad was no longer functioning, and the tips suggested elsewhere on forums did not help. Eventually I found the problem. It is a program called mouseemu which made the device unusable (busy) in X. The error reported in /var/log/Xorg.0.log was:
(WW) Synaptics Touchpad can't grab event device, errno=16
The solution is to deinstall mouseemu.
Also note that all touchpad definitions should be removed or commented out in /etc/X11/xorg.conf or else the scroll regions will not work. Configuring is now done using HAL.
