samba - Feb 2011 - Error copying users to Backup Domain using net vampire

Hi folks,

I am trying to migrate a 3.0 samba PDC to a new one using 3.4.9

My strategy is: install a new machine as a BDC and then promote it to a PDC.
PDC is using LDAP backend.

The BDC installation was fine.

I can see it using testparm.
And I can also enter the domain

 root at linux13:~#net rpc join -S 192.168.0.11 -Ujosir%xxxx
 Joined domain: MEDIASYS.

The problem: net rpc vampire is not working. I issue:

 root at linux13:~#net rpc vampire -S 192.168.0.11 -W MEDIASYS -U josir
%xxxx
 Fetching (to passdb) DOMAIN database
 netlogon_creds_client_check: credentials check failed.
 credentials chain check failed
 Failed to fetch DOMAIN database: NT_STATUS_ACCESS_DENIED

Could a mercy soul help me or suggest a site or documentation ?
Or: Is this the best approach to migrate to a new machine ?

Thanks in advance,
Josir Gomes