Walter, could you please grab the logs with 2.2b driver installed and all 3 monitors connected. You can download the debug tool from here:
http://www.displaylink.com/support/ticket.php?id=269
The 2.2b uninstaller completely uninstalls the driver. The OS could cache some info about the displays previously connected and this could slightly alter the initial state making 2.1 not working too. The logs should help us identify the cause of the issue. Thanks