[Dovecot] Resource temporarily unavailable

[karpi.lists at email.cz]

Hello, Im using dovecot for ages and im happy..
but at now strange things happens:

mutt returns:
Error talking to localhost (Connection reset by peer)

so i started telnet:
alnagon ~ % telnet localhost 143
Trying 127.0.0.1...
Connected to alnagon.localnet.cz.
Escape character is '^]'.
* OK Dovecot ready.
1 login karpi blablabla
1 OK Logged in.
Connection closed by foreign host.


Last line "Connection closed" appears immediatelly after logging..

log says:
Oct 27 11:20:50 alnagon dovecot: imap-login: Login: user=<karpi>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured
Oct 27 11:20:51 alnagon dovecot: IMAP(karpi): setuid(1000) failed: Resource temporarily unavailable
Oct 27 11:20:51 alnagon dovecot: child 8537 (imap) returned error 89



my configuratilon runs on gentoo desktop and looks like:

alnagon ~ # dovecot -n       
# 1.0.3: /etc/dovecot/dovecot.conf
protocols: imap
ssl_cert_file: /etc/ssl/dovecot/server.pem
ssl_key_file: /etc/ssl/dovecot/server.key
login_dir: /var/run/dovecot/login
login_executable: /usr/libexec/dovecot/imap-login
login_processes_count: 1
mail_extra_groups: mail
mail_debug: yes
auth default:
  passdb:
    driver: pam
    args: *
  userdb:
    driver: passwd


very thanks for any hint..