OS X PDC 10.5.3> can’t add clients

Hi all I've been following a thread on discussions.apple.com ([url] http://discussions.apple.com/thread.jspa?messageID=7330186[/url]) for a while now as I've been having exactly the same problem as these folks and no-one seems to have found an answer. Basically, we can't add Windows clients to our 10.5 PDC. This works fine in 10.4.11 but since moving to Leopard I can no longer add them. It all seems to work; you get asked for a domain admin account to add the PC to the domain - if you then go and check WGm there is the newly created PC account in Computers - but then you get a nasty little dialog box that says 'An Internal Error occurred'. Checking the SMB log on the server you get the usual usual bits about authenticating the admin: [code] check_ntlm_password: authentication for user [diradmin] -> [diradmin] -> [diradmin] succeeded[/code] So it passes that bit but then you get this straigh after it creates the Windows Computer account: [code][2008/08/14 11:23:24, 0, pid=38159] /SourceCache/samba/samba-187.7/samba/source/passdb/passdb.c:lookup_global_sam_name(596) User TESTPC$ with invalid SID S-1-5-21-309373216-260935968-2293285358-3002 in passdb [2008/08/14 11:23:24, 0, pid=38159] /SourceCache/samba/samba-187.7/samba/source/passdb/pdb_interface.c:pdb_default_create_user(389) Could not get RID of fresh user[/code] Checking the PasswordServer DB with mkpassdb indicates that it has valid entry and it matches the ID in the Computer Account record - so what's this bit about the 'invaild SID' and 'could not get RID of fresh user"? Any ideas anyone? Info - XP SP3 or SP2, OS X Server 10.5.4 running on Intel