I recently received a new top case under warranty by Apple. It seems that during it's 1 day stay at Apple Apple decided to upgrade the firmware in the DVD drive. I wonder why they did that. I have a Ti 800 and I had previously had AA17 but not System Profiler shows AA21 Interesting. You folks who flash to AX you might want to make sure you back it back to AA before sending your machine to Apple for warranty repairs.