The mp3s that I have downloaded from iTunes are "Copy Protected" and you can only play them on 3 different computers at any one time.   If you want to upload them to a new computer and play them on the internal CD player, you have to log onto iTunes and deauthorize one of the other computers, so it will no longer play that mp3.

So far, though, if I burn these mp3s to CDs, they play just fine on boomboxes and on components-type CD players. No limit on how many "mix" discs I make, and even if I burn the mp3s to a disc as "data files," the mp3s still play on most CD players (except really early models).   

I'm wondering if possibly the really new generation of CD players might be designed to reject the "Copy Protected" mp3s that you purchase on line if you burn them to a CD.    I'd think this would be problematic, since you're supposed to be legally allowed to make 3 copies (or at least 2) of an mp3 you buy from iTunes.   If it gets to where you can't burn your own mixes of songs you've acquired legally, that'll be a real bummer.   

So I'm hoping you just have a defective CD player, instead of this being a harbinger of things to come.

Genie