07-04-2012, 06:05 AM
RMXP does this with me sometimes too. There must be a certain format of mp3 that it can't handle. I've found putting a problematic file through Audacity (importing it then re-exporting) often solves the problem. I don't know what it is though, sometimes even RM2k3 flips out (the potentially infamous infinite "Not implemented." bug). Bit-rate? Certain tags? Album artwork?