I haven't forgotten about this... Going to try to get a case opened next week.

We're in the middle of a big cut-over, so it'll have to wait a week or so for me... feel free to send me a message or reply again here. I'll do my best to remember!

I have the exact same problem on 9.2(2)4.  If I use the key, auto-enable doesn't work; if I force password authentication, it does.