Attachment_fu mp3s

audio/mp3 will work better for you.

Best regards

Peter De Berdt

Actually - the correct mime type is ‘audio/mpeg’, not ‘audio/mp3’

http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7

http://www.iana.org/assignments/media-types/audio/

Cheers,
-Andrew