Disable your LW media player by going to LW's menu Tools>Menu>Player & unticking the option box & pressing the Apply button. Now your default mp3 player will play them & no issues. If you don't have a decent player try QCD which is free & has inbuilt codecs & plays anything: http://www.quinnware.com/ If LW is too busy downlding & uplding, etc. the media player can be compromised & not play properly.