samba - Oct 2004 - Using a single LDAP server to authenticate multiple Samba3 PDCs

Sorry if this is a FAQ but I have tried searching the web and both
samba3 books but I can't find  the answer.  I would like to use a single
LDAP server (openldap) to authenticate multiple Samba3 PDCs serving
different domains to authenticate Windows XP clients.  Ideally I would
like an XP client to appear in both domains and the user to get
different profiles depending on which domain they logon to.  Is this
possible and how do I treat SIDs etc?
We have Samba3/LDAP working with a single PDC/domain.
TIA
John Williams  
-- 
J.Williams
LHS
Aston University
B4 7ET UK