Hi Cdmcneil,
I’ve re-tested the custom files on a fresh Fuji installation, and the image slider header works fine on individual posts. Could you please provide a URL of your website so that I could look at the code?
Regarding the “Custom Header” box – it is situated right below the text editor area in the page edit mode (note that it is not present in posts, since posts do not have headers by default in Fuji). You can find a screenshot of the box in the theme manual, page 5 ;) Also note that this box is only needed if you wish to display a different type of header on a particular page than the one you’ve chosen in the Theme Options menu, “Header” tab – otherwise, if you want the same header on each page, just leave this box blank.
Sincerely,
Andrew | Satori