Hi,
Please run through this guide for general troubleshooting tips:
http://www.displaylink.org/forum/showthread.php?t=896
To help us investigate the issue, please download this tool:
http://www.displaylink.com/support/ticket.php?id=269
Run it and select "Gather Support Information" then attach the output.
It's also worth trying the "System Compatibility Check" to see if anything is flagged up.
Thanks,
James