No RID Set DN

[Murray Fraser]

I've got a problem with an S4 domain that started on 4.0.0 but is now on
4.0.5.

When I try to join a new S4 DC to the existing S4 domain, I get the error:

checking sAMAccountName
Adding CN=XXXXDC2,OU=Domain Controllers,DC=XXXXXXXX,DC=com,DC=au
Join failed - cleaning up
checking sAMAccountName
ERROR(ldb): uncaught exception - LDAP error 53 LDAP_UNWILLING_TO_PERFORM -
<00002035: ../source4/dsdb/samdb/ldb_modules/ridalloc.c:517: No RID Set DN
- Failed to add RID Set CN=RID Set,CN=XXXXDC1,OU=Domain
Controllers,DC=teysaust,DC=com,DC=au - objectclass: object class 'rIDSet'
is system-only, rejecting creation of 'CN=RID Set,CN=XXXXDC1,OU=Domain
Controllers,DC=XXXXXXXX,DC=com,DC=au'!ð> <>
  File
"/usr/local/samba/lib64/python2.6/site-packages/samba/netcmd/__init__.py",
line 175, in _run
    return self.run(*args, **kwargs)
  File
"/usr/local/samba/lib64/python2.6/site-packages/samba/netcmd/domain.py",
line 552, in run
    machinepass=machinepass, use_ntvfs=use_ntvfs, dns_backend=dns_backend)
  File "/usr/local/samba/lib64/python2.6/site-packages/samba/join.py", line
1104, in join_DC
    ctx.do_join()
  File "/usr/local/samba/lib64/python2.6/site-packages/samba/join.py", line
1007, in do_join
    ctx.join_add_objects()
  File "/usr/local/samba/lib64/python2.6/site-packages/samba/join.py", line
499, in join_add_objects
    ctx.samdb.add(rec)


When I try to delete a non-existing server record from the Configuration
naming context using ADSIedit, I get:

'Operation failed. Error code: 0xca  Cannot find attribute rIDSetReferences
of CN=XXXXDC1,OU,Domain Controllers,DC=XXXXXXXX,dc=com,dc=au'

Any suggestions on how to recover from this would be appreciated.

- Murray