The update for WMR solving your problem is scheduled to be released.

As for HD, I've downloaded a part of the following stream using one thread only
rtsp://rmv8.bbc.net.uk:554/scotland/radioscotland/demand/travelfolk/rs_travellingfolk_thu.rm

After that I've renamed rs_travellingfolk_thu.rm.@@@1 to rs_travellingfolk_thu.rm and had no any problem playing it with Windows Media Player Classic (using Real Alternative)