[Dovecot] Trouble with Dovecot

[Paul A. Novojeeloff]

Hello!
I'm trying the Dovecot as IMAP server, so I have one problem: I can log
in to server, but nothing appears in mailclient and following message
appears in log:
imap(user): Feb 08 20:36:34 Fatal: We couldn't drop root group
privileges
dovecot: Feb 08 20:36:34 Error: child 21356 (imap) returned error 89

What could be wrong?
Thanks for your answer.

WBR, Paul.