memory stick suddenly refuses to play MP3s

[jpwalser]

I used to be able to download and listen to MP3s on my CLIE N710C memory stick just fine. Now I can still copy MP3s to the memory stick, but I cannot play them anymore. Out of the blue! (Or should I say pink?)

Very recently, I discovered that my pink memory stick will no longer play MP3, and Sony OpenMP doesn't even open my memory stick device any longer. It complains: "The media is not available because it lacks copyright protection or is invalid"

I can copy the files onto the memory stick just fine (after mounting the device). But the MSAudio Player complains:

"This track is not available because either of the following reasons:
Does not support the copyright system.
...
The track file is broken".

I'm not sure if it could be the track file. But why would it suddenly refuse to play MP3s?

Thanks for any ideas, Paul