[dnanian]

I have no idea what happened here. It sounds, to me, like it started up from some other drive that was running a version of OSX earlier than 10.4.6 (which, as I recall, is when the startup disk started being listed in the "About This Mac" panel).

Why it didn't even give you a menu when you held down "Option", though, I can't say. That's a ROM/Firmware feature, and it certainly should have!