[Samba] Reestablishing trust with PDC

[Devon Crouse]

I often change configurations in a home server environment, and have scripts
to back up all config files etc. - on a fresh OS install I can quickly
restore function of all the services I'm running.

I'm using version 3.4.7 as a PDC on Ubuntu with 4 Windows 7 clients.  I can
restore smb.conf which gets the file shares and server configuration back,
but I lose the trust relationship with the clients and I can't figure out
how to get it back (short of completely clearing all the profiles and
dropping/adding to the domain.)  I'm making the following assumptions:

 - There must be some sort of signature for the Samba/OS installation that
changes
 - This signature must be recorded in Windows somewhere for it to validate
the relationship (like known_hosts)

I've tried the following in just about every order you can imagine:

 - Modifying/removing the profile registry entries in Windows
 - Removing/restoring the user directory in Windows
 - Removing/restoring the profile.v2 directory in Ubuntu
 - Experimenting with various local policy settings in Windows
 - Re-adding client to the domain
 - Using smbpasswd to recreate the users

There must be something I can backup/change to retain/reestablish the trust
relationship without having to scrap all the user profiles?  Thanks in
advance - all my reading so far has been of little help.

-- 

Devon