I would look at the player and at the sound server closely. First, you can try download/compiling/installing the most current version of the player. Second, you can try changing sound servers ( say, from ALSA to OSS ) and see if that helps. Third, you can just use the Yum ( yellow dog updater, http://linux.duke.edu/projects/yum/
) to upgrade everything. Fourth, you can check you mp3 source by playing it on another computer, I read all of mine from a network drive, but maybe you are playing from a CD or some other storage device.
Just a few ideas to help you solve your problem.