header image shows twice on a product page /header.php edit not show on all page

I’m stumped.

I’m using a child of twenty twelve.

Stuck on 2 things:

#1: I edited my header and footer.php files to include page divider images as seen here:

http://www.iconoclasticpress.com/draft/

However, it only shows up on that page, and not on any of the others although when I examine the source code, the inserted <div> is there on each of them. Why isn’t it visible? What’s special about this one page that it doesn’t show up on any of the other pages?

#2: My header image is showing up twice on the single product pages (changed to books). If you click thru books to one of the two titles, you’ll see a second, distorted version of the masthead on the page. What gives? I’d like to remove this.

I have not even begun copying or editing any woocommerce files so I doubt it’s one of those files. Still, how do I determine which php file is being called in when I see something I do not want or wish to change like this?