launchd?

Forgot to mention one thing: neither BIND nor Postfix runs with a Startup Item in Tiger, as they did in previous versions. They use launchd instead. Here's a page that describes how to get BIND started in Tiger (you still need to know how to configure it though):

http://www.dan.co.jp/cases/macosx/tiger/bind-tiger.html

And while I'm editing, I might as well give a link to his postfix page too:
http://www.dan.co.jp/cases/macosx/tiger/postfix-tiger.html