Motzarella via Thunderbird

I've been reading newsgroups via nntp.aioe.org (which is a somewhat
surreal experience in itself, given the random way in which it chooses
to ignore posts), but this morning it won't talk to me, and I have a
paper deadline tomorrow, so I'm desperately in need of procrastination
aids. Several people here have mentioned Motzarella favourably, so I
signed up with them. No problem.

My trouble is I can't get Thunderbird to request authentication. I've
checked Tools -> Account Settings -> Server Settings -> Always request
authentication when connecting to this server, but it doesn't seem to
have any effect. Is there something blindingly obvious I'm missing? I
could read via GG, but that only exacerbates my stress level.

--
Jen