Some questions for your debugging process...
Is the smb script still in /etc/rc.d/init.d? If so, is it executable? What do you get when you check the service with chkconfig (try man chkconfig)? Are there errors in /var/log/messages, /var/log/syslog or /var/log/samba/* ? What is the output of:
ps ax | grep '[sn]mbd'