I found I needed to upgrade the server from Red Hat 7 (or 8) to run a more contemporary version of Linux. Main reason is that the machine running Red Hat simply refused to restart after replacing the LAN card. I simply wanted to upgrade from 10 mbs to 100 mbs. That led down a long and tortuous path to build a new server, based on Fedora Core 6.
Everything seemed to get installed and started just fine: Sendmail, Apache, Samba file shares, etc. However, getting Samba to act as a domain login controller just would not work. I'm convinced there is a bug. I guess I will try to collect the information in the logs and send it off to the Samba developers.