I don't know about the bios, and I can't speak to Gutsy as that
computer died, but on Hardy the touchpad settings are under System >
Preferemces > Mouse > Touchpad. Unfortunately, there is no slider to
adjust sensitivity, but there are check boxes for enabling the
touchpad (good) and enabling mouse clicks with toutchpad (bad).

I have disabled touchpad clicks on every laptop I have ever had. Some
of them would jump the cursor when I hit the spacebar!