[Dovecot] log error file ioloop.c assertion failed

pop3-login process have some error like that log:

dovecot: pop3-login: file ioloop.c: line 22 (io_add): assertion failed: (fd >= 0) dovecot: child 4648 (login) killed with signal 6

Any idea ?

Thanks

-- Net4all S.A. Dominique Feyer Administrateur Système Ch. de la Colline 5bis CH-1007 Lausanne dfeyer@net4all.ch