This is a strange one. I found after getting back from Australia last week that whenever I boot my Mac Pro it opens the DVD drive before continuing to boot. This is the chain of events: Press power button on front of tower The chime sounds from the internal speaker; a solid grey screen appears The DVD drive opens (and stays open) The darker-grey Apple logo appears at the centre of the screen The system continues to boot to the log-in screen. Anyone got any ideas about what this is or how to fix it? When I originally tried to update the EFI firmware I found that the DVD drive would open and the firmware wouldn't update; that was fixed when a new version (i.e. third version after the release of the Mac Pro) of the EFI firmware came out my machine updated just fine. I tried resetting the SMC controller using the button on the Logic Board, but this seems to have had no effect. Earlier today I ran a software update and found the new version of the SMC firmware waiting for me; I downloaded and updated that, and the DVD drive opened in exactly the same way before the progress bar appeared to update the SMC firmware. Pretty odd!