Help with wmrecorder: stream with authentication gives "RTSP 401 Unauthorized" error

[monoi]

I have a subscription to a web site with embedded windows media player,I have no problem to download video concerning the channel 3, but with other channel (ex:5) WM Recorder in ada mode starts, finds the url, but the downloading doesn't start. It's cancelled after few second. The only difference between channel 3 and 5 is a choice of video quality (channel 5) between 256 OR 700 KBS through 2 buttons on the page.
If somebody could help.
thanks a lot.

P.S.
with URL Snooper the log indicates an 401 error (authentification error).