I think I figured it out...(am I the only one using the RSS feeds?)
Anyway, with Thunderbird, all threads come in looking like emails, but
the body of the email is actually the FSM forum. When a new thread is
posted, the "thread/email" becomes "unread" again. So you can see new
activity, kinda like in the old forum.
The only wierd thing is, sometimes I get duplicate threads...haven't
figured out if there is a pattern of behavior with that, yet...