dovecot - Oct 2004 - 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