I have may be the same problem.

I encode a live TV (with the WinFast2000 XP TV card by LeadTek) with WM encoder 9. I was able to stream it X50v running 2003se. It no longer works when I upgraded to WM 5. I could still stream it with a desktop version of Media Player 10 though. I put in the URL xxx.xxx.xxx.xxx: port (IP: port). Does anyone have a solution?
My error message is:
Cannot play the file. The file is either corrupted or the Player does not support the format you are trying to play.