[Dovecot] Strange config behaviour while using /etc/dovecot/auth.d/somename.auth

[Mark Alan]

While using Ubuntu 10.10 + Dovecot 1.2.12 + Postfix 2.7.1-1:

To export the authentication interface to Postfix, besides the usual
smtpd_sasl_* lines at postfix, I am using: the
following /etc/dovecot/auth.d/somename.auth file:
socket listen {
  client {
    path = /var/spool/postfix/private/auth-client
    mode = 0660
    user = postfix
    group = postfix
  }
}

But after restarting dovecot and doing a 'sudo dovecot -n' I get:
...
 socket:
    type: listen
    client:
      path: /var/spool/postfix/private/auth-client
      mode: 432
      user: postfix
      group: postfix


As 660<>432, is this Dovecot 1.2.12's  expected behaviour?

Thank you.

M.