zombie messages, nnimap offlineimap

[Uwe Brauer <oub@mat.ucm.es>]

Hello

I use offlineimap, dovecot  and nnimap to read my email on
my university email imap server.

My setting is very similar to the one described in 
http://www.emacswiki.org/emacs/GnusGmail


Now there is a annoying thing. After deleting mail on the
Uni imap server, say with thunderbird and then running
offlineimap (at least two times), the corresponding messages
are also deleted on my dovecot server (I check that again
with thunderbird connected to the dovecot server)

However some emails remain in gnus!
I have set the agent to nil hand have run 
gnus-group-get-new-news various times.

Either 
C-u g 
or simply by g.

It seems I have to regenerate that group but the nnimap
backend does not allow it.

By the way:

I looked up the documentation but cannot find a explination
for the star which appears in the group buffer on the left
as in 
*            0: nnimap+UCM:INBOX

Thanks

Uwe Brauer