[Samba] Transitioning NT groups?

[samba at schwartz.shutdown.com]

So, I'm in the process of transitioning our NT domain controllers over to
Samba. I've never tried to get Samba to act as a full PDC before, so this is
new territory for me. We still have a number of NT servers (not DC's) that 
have various directories owned by various NT groups and have various
permissions referring to groups, which unfortunately have to remain NT.     
   
I currently have Samba configured to get the username/machine information
from LDAP, and that's working great so far. One good thing that I don't  
really need to worry about is that we have all of the user/host/group/etc   
information in LDAP already, and I've written programs to keep NIS updated
with information from LDAP, and we have a synchronization plugin on the   
current PDC that also keeps stuff updated from the same LDAP information.

The problem is that whenever I have an machine capable of NTFS, and I go to
security for a file or directory, and try to give some level of access to  
users and groups, I see the users come up, but no groups besides the well  
known groups appear. If I can not somehow get Samba to serve up that list of
groups, then this will definitely be a show stopper for me. It doesn't
matter to me whether Samba gets the group information from LDAP or from NIS,
but it does need to show that list somehow. I've done my best rummaging
through the documentation, searching the web, wading through the lists, and
haven't been able to find much. I'm hoping there's just something I'm
missing, and someone can point out where I'm screwing up fairly easily, and
any help and/or suggestions would be greatly appreciated.

Thanks!
Matt Burgoon