I am using a HTML header and it appears fine on the main page and the Gallery page, but does not appear on the page of each of the individual galleries. Any advice.
My page is georgiamountainphotos.smugmug.com
Do you by any chance have your galleries set to appearance smugmug? They need to be appearance custom in order to show your customizations.
That setting is in customize gallery, in the look & feel section.
Also - you need to update the navbar entry for your galleries. You have it defined as
<a href="/Galleries">Galleries</a>
but according to your css, it must be
<a href="/galleries">Galleries</a>
--- Denise