[Dovecot] dovecot bug - kevent(EV_DELETE, 9)

[Mail.ru]

Sorry for my english.

FreeBSD 7.0-STABLE
dovecot-1.1.2_1 (from ports with LDAP)
AD LDAP на Win 2003 SP2 (work via GK)
CPU 2xIntel XEON
NFS not used

LDAP part of dovecot.conf (if you need all file, l'll send it):
auth default {
mechanisms = plain login 
    passdb ldap { 
            args = /usr/local/etc/dovecot-ldap.conf 
        } 

        userdb ldap { 
            args = /usr/local/etc/dovecot-ldap.conf 
        } 
        user = nobody 
        count = 1 
        ssl_require_client_cert = no 
        ssl_username_from_cert = no 

        #Postfix Auth 
        socket listen { 
            client { 
                path = /var/spool/postfix/private/auth 
                mode = 0660 
                user = postfix 
                group = postfix 
            } 
        } 
}

Whole dovecot-ldap.conf:
hosts = 192.168.8.5:3268 192.168.8.6:3268
dn = CN=SomeUser,OU=SomeOU,DC=domain,DC=ru 
dnpass = password 
tls = no 
debug_level = 0 
auth_bind = yes 
ldap_version = 3 
base = DC=domain,DC=ru 
deref = never 
scope = subtree 
user_filter = (&(mail=%u)(objectclass=user)(memberOf=CN=Mail,OU=SomeOU,DC=domain,DC=ru)) 
pass_filter = (&(mail=%u)(objectclass=user)(memberOf=CN=Mail,OU=SomeOU,DC=domain,DC=ru)) 
default_pass_scheme = CRYPT

My problem.

dovecot works fine with AD! but i have this in logs (This not nice,
but no more):
Aug 14 02:21:03 somecomp dovecot: auth(default): LDAP: Connection lost to LDAP server, reconnecting
Aug 14 02:21:03 somecomp dovecot: auth(default): kevent(EV_DELETE, 9) failed: Bad file descriptor 
Aug 14 02:36:04 somecomp dovecot: auth(default): LDAP: Connection lost to LDAP server, reconnecting 
Aug 14 02:36:04 somecomp dovecot: auth(default): kevent(EV_DELETE, 9) failed: Bad file descriptor 
Aug 14 02:51:04 somecomp dovecot: auth(default): LDAP: Connection lost to LDAP server, reconnecting 
Aug 14 02:51:04 somecomp dovecot: auth(default): kevent(EV_DELETE, 9) failed: Bad file descriptor 
Aug 14 03:06:05 somecomp dovecot: auth(default): LDAP: Connection lost to LDAP server, reconnecting 
Aug 14 03:06:05 somecomp dovecot: auth(default): kevent(EV_DELETE, 9) failed: Bad file descriptor 
Aug 14 03:21:05 somecomp dovecot: auth(default): LDAP: Connection lost to LDAP server, reconnecting 
Aug 14 03:21:05 somecomp dovecot: auth(default): kevent(EV_DELETE, 9) failed: Bad file descriptor 
Aug 14 03:36:06 somecomp dovecot: auth(default): LDAP: Connection lost to LDAP server, reconnecting 
Aug 14 03:36:06 somecomp dovecot: auth(default): kevent(EV_DELETE, 9) failed: Bad file descriptor

docecot was launched with debug_level = -1 in dovecot.conf. If you
need this log (it's very big) - i send it too. But i don't see in it
something new (dovecot check connection when it lost and succesefully
reconnecting to AD LDAP).

I want to know:
What this event means?
Can i fix it and what to fix?