[Dovecot] Using ldap and pam

[Bo Lynch]

Having some issues with ldap logins. I am using Centos
5,dovecot-1.0.13-1.el5.rfx and openldap-servers-2.3.43-25.el5_8.1
Trying to get this to work with the SoGo interface. First I converted all
my standard system users to ldap using the openldap-tools. This worked
fine, however when a user changes there password they can no longer see
there email. If they change it back to the original password mail can be
seen. This has stumped me for a day or so so I was hoping someone could
shed some light.
/etc/dovecot.conf
protocols = imap imaps
disable_plaintext_auth = no
mbox_read_locks = fcntl
mbox_write_locks = fcntl
protocol imap {
}
protocol pop3 {
}
protocol lda {
  postmaster_address = postmaster at example.com
}
auth default {
mechanisms = plain login
  passdb pam {
  }
  passdb ldap {
    args = /etc/dovecot-ldap.pass
  }
  userdb passwd {
  }
  user = root
  user = root
  socket listen {
    client {
      path = /var/spool/postfix/private/auth
      mode = 0660
      user = postfix
      group = postfix
    }
  }
}
dict {
}
plugin {
}

/etc/dovecot-ldap.conf
hosts = 127.0.0.1:389
sasl_bind = no
auth_bind = yes
auth_bind = no
ldap_version = 3
deref = never
dn = cn=sogo,dc=ameliaschools,dc=com
dnpass=password
base = dc=ameliaschools,dc=com
scope = subtree
pass_attrs = uid=user, userPassword=password
pass_filter = (uid=%u)