There seems to be an issue with Firefox 188.8.131.52 and iTunes 7.6 on OS X with regards to M3U files. I've noticed this issue with eMusic as well. To solve this, I've included the URL of the actual streams, and if you enter that URL in Advanced --> Open Stream, that should work. There's also this script, but I haven't had a chance to try it yet.
Note: This problem seemed to resolve with iTunes 7.6.1.
It's good to see the sappy Velvet Revolver song make the bottom list. It's just a boring song to me. I was wondering what the second single from Keane would be. I love the first seven songs from their album, so they can't really go wrong with me.