After installing samba from my red hart linux cd, my ethernet card was no longer available. The reason was that somehow the installation changed my /etc/conf.modules to /etc/conf.modules.bak. The solution was to copy the bak file to the a new /etc/conf.modules.
The samba package doesn't touch /etc/conf.modules, so the problem here is with the installer. You will always need to restore any local configuration changes from save files after completing an upgrade.