Hi,
Regarding response time to your message please see this page:
http://www.displaylink.com/support/index.php
What I need to know is:
What application are you trying to play protected content through?
What kind of protected content are you trying to play?
I'd advise using the latest WHQL signed version of your graphics driver. Beta versions have been know to show up such as those you describe.
Thanks,
James