Did you run sax2 from the desktop as Administrator with Yast or did you go to console mode, type su to become root, then use the command sax2 -r? The latter will make a new search for and reconfigure your mouse, screen, touch pad, etc. The same GUI should appear as when starting from the desktop with Yast, and you are presented with the settings the GUI gives you, but perhaps with a better identification of the device. Look at all the boxes or links for expert or custom modifications.
Opening a terminal and typing man sax2 will give you more information as will google. I do not have a touch pad, but I would think that sax2 might treat it much the same way as it does a 5-button mouse. You might try that approach if sax2 does not configure the touch pad directly.