samba - Sep 2009 - How to get Default builtins added?

I recently decided to upgrade to the tdbsam: backend, but I'm
missing the built-security principles.

Do I need to go back to the smbpasswd backend, and add them in
the file *first* before converting?

I had them there at one point, but I think I think I deleted 
them because they weren't working.  Cygwin's mkgroup command
couldn't
seem to pull in the groups from my samba server). But, by default, 
files I create through the 'gui' get created with group '513'
(Domain
User).

Any scripts to add the default principles to a newly
converted TDBSAM?

Thanks for any help...been hitting the Samba-3 howto book and
the pdf updates and man pages to no avail, and my fingers are 
falling off (sigh).

linda

FYI -- I tried adding then with pdbedit but it said they don't exist
in /etc/passwd -- but they 'do'...just with not the same exact names.

I was going to use the 'map' command to map the names from the tdbsam
to the unix side, but I have to get them into the tdb sam first.

Also, I really wasn't clear about how I am to add the principles -- 
I know the form of the sids, but isn't a large part of it to be
filled in by the samba-server when I add the user?


tnx 
-l