Hi, I have a 24" iMac that I formatted and clean installed Lion 2 days ago. It only has Lion, iWork, iLife and CS5. The DVD works fine and I can burn music CDs in iTunes and play them on the iMac but if I put in a normal music CD it whirrs for a bit and then chucks it out. I have tried with old CDs, brand new CDs and nothing works. Any ideas?