I'm not sure what beta Targus has sent you, but can you try the new v7.0 Beta on our website here:
http://www.displaylink.com/support/downloads.php
If the problem still occurs, can you see if it happens on both USB 2.0 and USB 3.0, or just USB 3.0. Will help us narrow down where the issue is, if not already fixed in the beta.
Wim