I removed the overenthusiastic authorization check at the beginning of
posting... it's *supposed* to let you post or reply even before you're
officially signed up, as long as you give it enough (name/email) for
Lazy Registration. It then sends your message to moderation. But
because I'm stupid, it was checking authz *before* doing the
registration and posting, and just denying the message. It may be
working now; I haven't had time to test it yet (since, as I mentioned
to Dieter, this *is* my dev/test setup right now. I need to change
that). 

There's still a persistent bug in posting messages, where it makes the
post, then turns around and gives a 404 when trying to display it. This
isn't right, and I have some debug logging to try to track it down
soon.