[Dovecot] 1.0-test46: Assertion failed

Hi,

I'm experiencing there assertions in the mail log (about 8 times during the last 2 days):

Oct 5 11:20:51 web dovecot: POP3(xxxxx): file mbox-lock.c: line 493 (mbox_lock): assertion failed: (lock_type == F_RDLCK || ibox->mbox_lock_type != F_RDLCK)

What is it? I'm running 1.0-test46 and sendmail on FC2. This is in dovecot.conf:

#fcntl_locks_disable = no #mbox_read_locks = fcntl mbox_write_locks = fcntl

Thanks.

Martin