[Tigga]

Which method did you use to change it? If you used the 2nd way so it would just call your regular header, I forgot that you would need to change "$index_header" to "$header" in your index template (sorry, it's late ).
If you used the first method, I'm not completely sure why it wouldn't have worked. You said you used a php file for your header... Is there maybe a place to set a path to the file or something like that? If you could post the header & phpinclude templates or email them to me (brian@plurplanet.com) so I can have a look I'll see if I can figure it out. Or you could try the 2nd method to include it, which really is better if you want to have the same header for your forums and index page. That way you don't have to edit both anytime you change it.