[Samba] UID/SID mapping across PDC member servers?

[Sven Riedel]

Hi,
I have a Samba 3.0 beta server set up as an NT Domain PDC (lets call it
box S), a Windows 2000 client (box W) and a Linux member server in the
domain (box L). All are configured as per the most recent 3.0/HEAD howto. S and L have the same users with same UIDs and login names in /etc/passwd and /etc/shadow.

When browsing the domain from W, I can access all the shares on S and L.
On S I can access the shares as the user I log into to the domain with.
On L I can only acces the shares as "nobody" (/var/log/samba/log.smbd
states that the UID/GID was mapped to 10001/10001). How do I make L
realize that the user logged in is the same user as the one with the
same UID on S? I tried experimenting with the "usermap" file (trying 
user = user DOMAIN/user), but that didn't succeed. Any ideas? 

Regs,
Sven

P.S. Please CC me, as I'm not subscribed to this list.