[Samba] the user name could not be found

[Mohammad Reza Hosseini]

hello
I had a samba and a PDC  running very well with a LDAP server until we
decided to change the pdc domain name.
so i changed the "wrokgroup"  parameter in smb.conf file and used the
smbldap-populate for adding the  domain to LDAP.
but when we tried to join winxp computers to the domain it gave an error:
"The user name could not be found" any help?