Looks it could be due to some HTML5 problems in Abrowser. If you go to this
page
http://bandcamp.com/html5
and click the button, you get this message:
"Sorry, but unfortunately, your browser does not support HTML5 audio in the
format we need. Maybe someday it will, or we'll add more supported formats,
or something else will happen."
Ah, hang on... "the format we need"... does that just mean that Abrowser
deliberately won't stream mp3?
I just found this thread
http://trisquel.info/en/forum/how-enable-mp3-support-html5-abrowser
which sheds some light on the subject (before getting flame-y).
Still a bit confused though.
Waiting for the glorious Opus transition.