Uhhh you wont believe this, but I had the same mp3 player, and for some reason it did the same thing to me as well. Its the file, the mp3 player wont allow you to play certain songs or files, and yeah the mp3 player is bugged, something about the chip or whatever, so I returned mine and got a new one. I suggest you go to the store from where you bought it and explain it to them, and they will switch it out. Got mine from Circuit City.

Edit: Its like the X-Box360 errors