samba - Oct 2007 - Upgrade to 3.0.25c security = user machine creates its own domain??

Hi,
I just upgraded to 3.0.25c and a samba file server that I have set up
as security = user suddenly created its own domain and a new
sambaDomainName entry in my LDAP database. This also had the
side-effect of breaking all my per-user authentication shares (because
now the users appear in the new domain as opposed to the existing
one). I've worked around this by setting the localsid of the machine
as the existing domain SID. However, I'm sure this is not the proper
solution.

How do I make this machine get back into my existing domain?
net join on the domain gives me the following error:

[2007/10/05 15:44:58, 0] rpc_client/cli_pipe.c:get_schannel_session_key(2449)
  get_schannel_session_key: could not fetch trust account password for
domain 'TOUCHTABLE'
[2007/10/05 15:44:58, 0] utils/net_rpc_join.c:net_rpc_join_ok(70)
  net_rpc_join_ok: failed to get schannel session key from server pdc0
for domain TOUCHTABLE. Error was NT_STATUS_CANT_ACCESS_DOMAIN_INFO
Join to domain 'TOUCHTABLE' is not valid

Thanks.

-- James