Docking with X200 Ultrabase question?

Okay, here's the situation:

I recently purchased an Ultrabase for my X200 to use it as a desktop docking solution.
I'm running dual monitors; a 20" Dell LCD via the Displayport and a 17" HP LCD off the analog.
The Dell monitor has a USB hub I've connected my external HDD, printer and scanner into; I have a keyboard and mouse plugged into the Ultrabase.
I'm running into a strange issue:

Whenever I try to undock the X200 while pressing the button, the undocking process inevitably fails, pointing to a "Generic USB Hub" as the culprit.
Even after unplugging everything but the monitors from the Ultrabase I still get the same error? Has anyone else encountered this problem?

Movies 24h | Dmart.vn