My Dell laptop at work has both a nipple and a touchpad.
Used to have a "wandering cursor" problem and the temporary fix recommended by our IT folk was to disable the nipple, and use the touchpad only. Did that, and it worked absolutely fine.
The permanent fix was to replace the keyboard. The engineer explained that one of the ribbon cables connecting the keyboard to the motherboard wasn't sufficiently shielded, and so the keyboard was interfering with the nipple and sending it false signals.
Keyboard replaced, nipple re-enabled, all works fine now.
RC