There seems to be an issue with Firefox 18.104.22.168 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.
To be fair, it wasn't RS writers who compiled the list. I agree, that would be horrendously stupid and worthless. While they only name a couple names, they state that the list was compiled from the votes of 172 music industry types.