Kirk - Thought you'd like to know. Just got off the phone with Apple Care. All fixed. Woo-hoo, I did not have a hardware problem They had me start up from the original install disk. Then repair the HD and Repair Permissions. Then restarted from the my system HD, and had me toss both the caches in my main Library as well as the caches in my Home Library. After restart: everything is hunky dory. He said that I had a corrupted preference file. The System profiler again senses the Pioneer drive both under ATA and Disc Burning. And I can write an audio CD from iTunes and a data CD from Finder. I'm a happy camper again. John