speeding page loading times?

I switched to a new theme, and I would like to simplify page loading so that it is faster and more visually appealing.

For some reason, the background, header images, content container, general layout in my new theme are not cached in the browser, but re-load for each new page view. I’ve searched the code and compared it to other templates, and I cannot find a solution to this. In my old theme, the static elements remained visible on the screen, while the new content changed (for each new page view). I would like my current theme to function this way. Any advice?

My blog: Northern Waterways