/usr/lib/firefox-3.0.1/defaults/preferences/all-redhat.js

with:

pref("app.update.auto", false);

pref("app.update.enabled", false);

pref("startup.homepage_override_url", "");

pref("startup.homepage_welcome_url", "");

The only changes are the '''last three lines'''. The first one is obvious, but the other two are set to blank urls so that the (annoying) Fedora and Firefox welcome pages don't appear. Instead the first page people see is Amahi.org.