[Samba] cannot join to domain

[rpenny at f2s.com]

I am trying to set up Samba 3-0-22 as a PDC on Ubuntu server 6.0.6 LTS, this is
on a Sun Ultra 5. When I try to join the domain using root, I get a dialog box
with the following message

The following error occurred attempting to join the domain "domain name":
The user name could not be found.

When I looked inside /var/log/samba/log.hp-laptop I found this

[2006/10/10 19:07:02, 0] rpc_server/srv_samr_nt.c:_samr_create_user(2415)
   _samr_create_user:Running the command '/usr/sbin/smbldap-useradd -w -i
"hp-laptop"' gave 9

so I looked inside /usr/sbin/smbldap-useradd, I then found that the only exit
that gave 9 was the following

# user must not exist in LDAP (should it be nss-wide ?)
my ($rc, $dn) = get_user_dn2($username);
if ($rc and defined($dn)) {
  print "$0: user $username exists\n";
   exit (9);

I am now lost, as I understand it, root is the only way to join a domain and the
dialog box on my windows machine says the user cannot be found,
but smbldap-useradd seems to be saying because the user exists I cannot join.

I have tried reading the archives etc but cannot find an answer, anybody out
there know a cure for my problem?

thanks
Rowland