samba - Dec 2011 - Problems trying to add computer to a domain with Domain Admin Users

Hi 
I have a server with openldap and samba (samba3x in Redhat), but I can only add
users to the domain with the user Administrator.
I created some users with smbldap-useradd and the changed them to the groups
Domain Admins but I cannot add them to the domain except when I use
Administrator.

This is an example of the log of my user "jdc"

Error: modifications require authentication at
/usr/lib/perl5/vendor_perl/5.8.8/smbldap_tools.pm line 1207.
[2011/12/11 19:25:30,  0] passdb/pdb_interface.c:pdb_default_create_user(342)
  _samr_create_user: Running the command `/usr/sbin/smbldap-useradd -t 0 -w
"pcpruebas$"' gave 3

Thanks,

Juan Diego