Is it actually phoning home as opposed to pulling the drivers from your local system? Try the cleanup tool here:
http://www.displaylink.com/support/ticket.php?id=297
If that leaves behind something (it shouldn't), you could try RAPR to manually do it:
http://driverstoreexplorer.codeplex.com/
If it actually is updating from online, try installing Wireshark to monitor your traffic, you should be able to figure out what address it's looking up and block it that way.
In case it's old drivers related, try either the latest generic Synaptics v17.0.19:
http://www.synaptics.com/en/drivers.php
Or latest I could find Synaptics v18.1.3.0:
http://www.station-drivers.com/index...sion-18.1.3.0/
You might want to check that those drivers above have the hardware IDs for your particular touchpad in their *.inf file(s) before you install them, if you try going that path to potentially fix it.