Damn. I just got an 80gb problem and I'm getting this same error, but on a Mk2. Is it possible that with an 80gb drive it needs the extra 4mb found in a Mk2a? I was hoping to do the drive upgrade using my Mk2 so I don't have to sacrifice my Mk2a until the last minute (when I copy over the dynamic data partition et. all.)

Or is there some other cause of this? I've tried using both builder images (the "outdated" one and the "test" one.)