Milter-greylist

Hello,

I've installed milter-greylist 4.2.6 on server running RHEL 5.5
and sendmail 8.14.4.
When new mail message arrives I see  error messages in /var/log/maillog like these:

milter-greylist: smfi_getsymval failed for {i}
milter-greylist: (unknown id): Sender IP 127.0.0.1 and address <root@my_domain.ru>
are SPF-compliant, bypassing greylist

As far as I understand milter-greylist can't get   message queue ID but
don't know why.
Besides milter-greylist I use another milter, one for antivirus program 'drweb-milter'
Sendmail config sendmail.cf have such lines:

O InputMailFilters=greylist, drweb-milter
O Milter.LogLevel=6
O Milter.macros.connect=_, j, {if_addr}
O Milter.macros.helo={verify}, {cert_subject}
O Milter.macros.envfrom=i, {auth_authen}
O Milter.macros.envrcpt={rcpt_mailer}, {rcpt_host}, {rcpt_addr}
O Milter.macros.eom={msg_id}

Xdrweb-milter, S=local:/var/run/drweb/drweb-smf.sock, F=T, T=C:1m;S:5m;R:5m;E:1h
Xgreylist, S=local:/var/milter-greylist/milter-greylist.sock, F=, T=S:1m;R:1m

When I remove drweb-milter from  InputMailFilters then
error messages disappear.

BTW, on other server running RHEL 4.1, milter-greylist 4.2.6 and sendmail 8.13.1
such error messages are not observed.

What might be the reason ? Bug in sendmail 8.14.4 or something else ?
How to eliminate these messages ?
Any hints.

Thanks.