Another Update: As it turns out, re-registering your eDGe has at least one drawback: Doing so may result in having to re-authorize your eDGe with Adobe, whcih in turn may result in not being able to open purchased ebooks. I have one and only one Adobe ID, but since I re-registerd and re-authorized my eDGe, I can't open any of my purchased ebooks. I get an error message that says "This content is licensed to another user." Who, me?

I think the only solution is to reload all of them--sans annotations. Someone correct me if I'm wrong.

Such. A. Pain.