in the imap.log:

imap(arvays): May 28 10:39:32 Error: Timeout while waiting for release of fcntl() lock for index file /home/arvays/Maildir/.INBOX/.imap.index

imap(lfarkas): May 28 10:42:05 Panic: unreached

dovecot: May 28 10:42:07 Error: child 19933 (imap) killed with signal 6

-- Levente "Si vis pacem para bellum!"