I started a blog with the theme twenty ten. When I clicked on the pictures in one of my posts, the pictures showed up with a black background. Now I made a new site with the same theme, but when I click on the pictures they show up like a post with header, comment box, widgets etc. How can I change that? I imported some posts from my old site too and the pics show up as before (with a black background). Why the new posts don't?