Has anyone else run into this? I just got a new iMac last week. I already had a decent audio system (Altec Lansing) from my old Dell PC. However, once I hooked up the sound system to the Imac, I started hearing an a radio broadcast in the background whenever I started Itunes. Itunes works fine, but the background radio is obviously something I don't want. Any thoughts? Thanks for any help or suggestions.