If you have the MP3 option enabled (which I'm guessing you do), you can only play MP3 CDs from the drive in the dash. The 6 disc changer will NOT play MP3 CDs. If that isn't the problem, take it into the dealer. I believe there is a SIB for that, but I'm not sure. Don't quote me on that.
Not putting miles on your Ferrari is like not f*cking your girlfriend so she'll be more desirable to her next boyfriend.