Thanks for the info - I've added this to the list.
For the H.264 stream try using VLC, not quicktime player to view the stream. The BBC are aware of the problem, and say this is a problem with the current version of quicktime player (bourne out by the fact it works in VLC) Note that you will need a reasonably powerful computer to decode H.264 streams.
@David Rickard ->
Have you tried the instructions in the PDF file for the 662HW? See the Multicast Router's sticky for the link.
Also don't forget to try different streams. If Real doesnt work then try the Windows media play and H.264 streams too.
Kindest regards,
James Sweet
http://www.zen.co.uk