[Samba] ldap_initialize: Bad parameter to an ldap routine

[grant little]

I searched and found this from Volker in 2007 same error message but the fix
didn't fix in my case:
http://lists.samba.org/archive/samba/2007-March/130093.html

my system: ubuntu 10.04 LTS server samba 3.4.7

error:
[2010/09/01 23:57:17,  5] winbindd/idmap.c:169(smb_register_idmap)
  Successfully added idmap backend 'ldap'
[2010/09/01 23:57:17,  0] lib/smbldap.c:716(smb_ldap_setup_conn)
  ldap_initialize: Bad parameter to an ldap routine

global section of config
[global]
  unix extensions = no
  disable spoolss = Yes
  name resolve order = hosts
  workgroup = AD
  realm = AD.MYDOMAIN
  server string = %h server (Samba, Ubuntu)
  dns proxy = no
  log file = /var/log/samba/log.%m
  max log size = 1000
  syslog = 0
  log level = 3 passdb:0 auth:0 vfs:0 idmap:5
  ldap debug level = 10
  ldap debug threshold = 5
  panic action = /usr/share/samba/panic-action %d
  security = ads
  kerberos method = system keytab
  encrypt passwords = true
  passdb backend = ldapsam:ldaps://ldap.ad.mydomain/
  ldap ssl = off
  ldap admin dn =
CN=ucenters-ldap,ou=users,OU=UCenters,DC=AD,DC=MYDOMAIN,DC=MYTLD
  obey pam restrictions = yes
  unix password sync = yes
  pam password change = no
  map to guest = bad user
  winbind enum groups = yes
  winbind enum users = yes
  idmap backend = ldap:ldap_url = ldaps://ldap.ad.mydomain/
  idmap uid = 10000-1999999
  idmap gid = 10000-1999999
  idmap alloc backend = ldap
  idmap alloc config : ldap_url = ldaps://ldap.ad.mydomain/
  idmap alloc config : ldap_base_dn =
OU=Users,OU=UCenters,DC=AD,DC=MYDOMAIN,DC=MYTLD
  usershare allow guests = no


Any hints?

Thanks.