media player 11 minor problem

I play oldies radio on my computer from time to time and have a
shortcut on my desktop for 'smokin oldies'. It used to bring it up
in MP11 without any problem. Lately I get this message:

Windows Media Player cannot play the file. The Player might not
support the file type or might not support the codec that was used
to compress the file.

I can go to the smokin' oldies website and click play and it plays
in wp11 without any problem. It's not a major problem but I
wondered what why this is suddenly happening.
I have Windows XP sp3 media center edition.
Any ideas? Thanks,
Janice