well this isn't just samba as a PDC it's also using an LDAP backend and LAM as a ldap interface. also it's on fedora core 3.
i've posted a few how-to guides on my local LUG website.
http://tlug.dnho.net/?q=node/146
the other option is to try my ServerSetup v0.06 script
http://www.geocities.com/evilperson85/serversetup.txt
just copy the contents into a file and make it executable
vi /home/serversetup
*copy the contents into that file*
chmod a+x /home/serversetup
and it's pretty easy to follow, the script is still in it's very beta stages, it's only been around for a few days, i'm still find better ways to do things and bugs in it and it was written for adding a linux machine to a windows domain, but it can't hurt to try, even if it dosn't work it'll put you on the right trace ... , so if you try it and it works or dosn't let me know by posting back here.