After the install my Mac locked up on boot, just before it should show the mouse icon. I pulled the firewire 800 cable connected to my Epson Professional V700 scanner and the boot completed.
After some experiments showed that I couldn't boot as long as the scanner was connected I power cycled the scanner. It was behaving oddly, I had to pull the power cord. After that I was able to boot.
I'm not sure the problem is fixed, Apple's Discussion board has a number of complaints:
- epson printer software update 2.14...: Apple Support Communities
- Bad print to new Epson after OS X update: Apple Support Communities
- Gordon's Tech: Obnoxious old Epson Scan bug: EPSON Scan cannot be started. 2/2008. Hmm. Strangely familiar.
- After four months of intermittent but increasingly odd boot behaviors followed by a few days of high frequency kernel panics the flat 400/800 adapter firewire cable connecting this scanner to my firewire chain split open. So, in retrospect, this may have been the start of the firewire cable failing. In future I'm going to do a routine restart before I do updates -- just to make sure things are working before I change software. There's a lesson here about the problems of complex configurations given the limited diagnostic capabilities of OS X.