samba - Nov 2006 - net view \\machine\Admin$ fails with "_net_sam_logon: creds_server_step failed. Rejecting auth request from client ..." on the samba pdc side

I am running my self compiled samba 3.0.21a PDC on centos 4.1.

My Admin shares seem inaccessible across the network.

When I do a "net view \\it-015\C$", or exactly same error for
\\it-015\Admin$ or \\it-015\IPC$ shares, I get an error as follows on
the win xp pro sp2 machine IT-010:

System error 123 has occurred.
The filename, directory name, or volume label syntax is incorrect.

And each time I do this the samba server logs "_net_sam_logon:
creds_server_step failed. Rejecting auth request from client IT-015
machine account IT-015$"

The IT-015 as well as my own, IT-010, machines were successfully joined
to the domain, and netdom on the two win xp pro machines also confirms
that the machines are properly part of the domain.

C:\>netdom /verify it-10 /Domain:MYDOMAIN /UserO:sysadmin /PasswordO:*
Type the password associated with the object user:
The secure channel from IT-10 to the domain MYDOMAIN has been verified.
 The connection is with the machine \\MYPDC.
The command completed successfully.

C:\>netdom /reset it-10 /Domain:MYDOMAIN /UserO:sysadmin /PasswordO:*
Type the password associated with the object user:
The secure channel from IT-10 to the domain MYDOMAIN has been reset.
The connection is with the machine \\MYPDC.
The command completed successfully.

Any ideas how I can fix my samba PDC so it also thinks my machines are
part of the domain, not just the machines themselves?

Thanks in advance.

-- 
Urs Rau