postfix+sasl2+db41+ldap21 port problem?

[Mauro Boschi]

Hi,
I'm trying to install postfix+sasl2+db41+ldap21 via postfix port on a
4.8-STABLE. Everything seems going well but I've notice a stange warning
during the sasl port install in the /var/log/messages:

Jun 22 00:28:23 bsd48 saslpasswd2: Could not open db
Jun 22 00:28:23 bsd48 saslpasswd2: Couldn't update db
Jun 22 00:28:24 bsd48 last message repeated 5 times

this happend when the sasl port was running ldconfig:

===>   Compressing manual pages for cyrus-sasl-2.1.13_4
===>   Running ldconfig
/sbin/ldconfig -m /usr/local/lib
===>   Registering installation for cyrus-sasl-2.1.13_4

the problem now is that I'm unable to correctly use the sasl layer.
There is something that I can do to install "in the right way" postifix with
sasl2?
What I'm doing wrong? I've test this on various system 4.8-RELEASE,
4.8-STABLE and 5.1-RELEASE...
I really need SMTP AUTH! : )
thanks
mauro