Well, AllTunes has been returning the same error for a couple days now:
FSOUND_Stream_Open error: Unknown file format
Which tells you a lot, doesn't it? Head over to ALLofMP3 and try a preview there, you will get:
Warning! Currently preview for this track is not available due to technical problems. Please check back later.
What had me totally freaked out was that I had coincidentally reinstalled Windows and all my software just before this started happening. I thought I had left out some codec or something that would be nearly impossible to nail down.
Why get so worked up in the first place? Because I just discovered ALLofMP3 and AllTunes a few days ago. It's an amazing service. And when you read how much effort the record industry and Microsoft are putting into restricting fair use of audio CDs, you want to get the most out of something like AllTunes while you still can.