[Samba] general questions about samba 302alpha

[Pouchoulon Jean-Marc]

I tried to use samba 3.0.2alpha in a ldap environment ( netscape 4 
diretory server ) with xp sp1 and window 2000 server as client.
I followed the ignacio coupeau tutorial's.
I have some questions about samba 3 architecture and nt 2000 in 
general.
Ignacio coupeau have 2 domain's logon, with exactly the same 
configuration.
it seems to work on my lan but I'd like to understand how.
I can suppose sid on the two netlogon server are different. How  the 
xp client deal with that ? specially when he joined the domain ? Where 
he stored the information ( locally , on the ldap directory ?) How can 
it find the domain logon ( I supposed with wins , my two domain 
logon’s are wins server and bind 9 cannot be used to find them ).
Where are the sid of the domain are stored ?
( I saw that if I stopped one server the other one answer, but 
sometimes the client cannot logon, ).
I have the same question with smbgroupedit. Group_mapping.tdb must be 
the same  on the two PDC ?
I lost the domain_admins_group on one server. ( I mapped 512 sid group 
with a unix domadm group but it works  either).

Any lights would be greatly appreciated.
thanks.