Hi James,
After having read the article you linked I believe that would be the potential cause. The cable supplied with the Targus is short, the notebook is only working connected to a wi-fi and the distance from the Docking to the internal antenna, could be hence too short. Therefore I think the noise caused be the 3.0 USB cable to the antenna is causing this issue.
I wonder how could I isolate as mentioned in the White Paper the targus...any ideas I could try? Plan B, get a longer 3.0 USB cable and hide the device?