[Dovecot] dovecot-1.0b3 kevent error/warning message

i use openbsd/i386, dovecot-1.0b3, i see some kevent error/warning message in maillog like this:

imap(username): kevent(1) in io_loop_handle_add() failed: Bad file descriptor imap(username): kevent(1) in io_loop_handle_remove failed: Bad file descriptor