I am using Ubuntu 9.10 Karmic Koala on my Desktop with Firefox 3.5 as my primary browser. Recently I was facing problems playing online media (streaming mp3s, non-flash) including FM from my own page on Firefox.
eMazza.com has a live music jukebox at http://www.emajja.com/emajjanew/index.php?page=music
You can play songs in the playlist, but what if you want to download it? You can do so by following this short procedure.