Yes, Fedora Core 5 has been problematic–the build of PHP4 I made for Fedora Core 4 doesn’t build for FC5. I have, just yesterday, completed a build of PHP4 for Fedora Core 5, and the FAQ will work–though there is one additional step that I haven’t yet added.
Instead of moving the /etc/httpd/conf.d/php.conf file to php.conf.disabled, edit it and comment out all of the directives (put a # in front of them), and then edit the php4.conf file and remove the # from in front of the LoadModule, AddType, and DirectoryIndex directives. Restart Apache, and things should work fine.
The reason for the change (which I’m adding to the FAQ right now) is that updates to PHP 5 would re-add the php.conf file and cause Apache to crash in odd ways (you can’t have php5 and php4 loaded by Apache simultaneously, though there are no errors on startup when you try to do so–I find that very disturbing, but we’ll just have to live with it).