I have a 7130c on Cingular, running app version 220.127.116.117 (dobson). I'm on a bes.
Try this link: http://www.geocities.com/jhselby/Angie.mp3
It's a free geocities account, so it's probably got some bandwidth usage restriction.
Listening to MP3s is not that practical as I can't save the file and lose it if I navigate away from the browser. But, it sure is nice to be able to download and view word docs from the interweb.