Well I know the changes I made to /forum/index.php have to be correct as I noticed that when I had the files empty and pointing at the right place the page loaded fine, when I purposefully made the path wrong it would not load.
But I have double checked config-inc (which must be fine as the gallery itself is fine?), config-int and I didn't find any changes that needed to be made to header-inc.
Is there anything else I might need to do??