We installed Samba 3.0.0rc4 from the binaries on redhat 9a with the latest 
updates from rhn. We configured the Samba as a BDC. We joined the domain. This 
works fine. We executing net rpc vampire we received errors for all users and 
machine accounts, that contained uppercase letters. The error message told us, 
that there is a problem creating the posix account. All other accounts 
(pcuser1, pcuser2 ..) which we created in the testing enviroment work well. 
The groups are added with the creategroup.sh script so there is no problem 
with uppercase characters. So we tried a similar script for users, changing 
the %u parameter to lowercase. Then all accounts are created, but the machine 
accounts didn´t work. We were unable to create new machine accounts. So we 
wanted to delete all users and start over again. But the our redhat 9 machine 
did not reboot. Everything in /proc was lost. This orccured two days before 
when we tested Samba 3.0.0rc4 as PDC on an other machine in the same way.

So we tried this on a redhat 7.3 machine. There it was no problem taking all 
accounts to the passwd.tdb database and creating all the linux accounts.