First, I am not a MAC user so I can only repeat what I have read here. The issue is not the file itself, your system has associated MP3 files with the application 'Limewire' there should be no need to convert the file it is what it is, an MP3. There is a method that has been described in these forums before to tell your system that these files need to be associated with whatever application you use to play MPs.... I think a lot of MAC users use itunes. At any rate try searching the MAC areas ... the last time I saw such a message was in July so it should not be buried too deep.