[Dovecot] Unexpected input from auth master: CUID

[Branislav Baca]

Hello,
I'm using postfix(2.4.5) and dovecot(1.0.5), and till now I have been 
using postfix deliver agent. Now I have tried to reconfigure postfix to 
use the dovecot LDA, but I'm getting some strange error:
Sep  9 18:07:57 hostname deliver(username at domain.tld): BUG: Unexpected 
input from auth master: CUID^I5

For IMAP and POP3 my configuration works fine.
I have tried it also with dovecot versions 1.0.4 and 1.0.1, but the 
behaviour is the same.
What can be the reason of this? What should I look for to get more 
details what can causing this?

I have this line in postfix master file:

dovecot   unix  -       n       n       -       -       pipe
  flags=DRhu user=mails:mails argv=/opt/dovecot-1.0.5-1/libexec/dovecot/deliver -f ${sender} -d ${recipient}


In main.cf:
dovecot_destination_recipient_limit = 1
virtual_transport = dovecot

Relevant parts of dovecot.conf:

auth default {
    passdb sql {
        args = /path/to/dovecot-sql.conf
    }
    userdb sql {
        args = /path/to/dovecot-sql.conf
    }

    socket listen {
        client {
          path = /var/run/dovecot/auth-master
          mode = 0600
          user = mails
          group = mails
        }
    }
}

protocol lda {
    postmaster_address = postmaster at domain.tld
    auth_socket_path = /var/run/dovecot/auth-master
}


And relevant parts of dovecot-sql.conf:

driver = mysql

password_query = SELECT address as user, passwd as password FROM 
mail_users WHERE address='%u'
user_query = SELECT CONCAT('/home/',maildir) as home, 999 as uid, 999 as 
gid FROM mail_users WHERE address='%u'




Thanks,
BB