Container Ends Prematurely?

On any page of my new blog (first WP blog, thanks for the patience) where the post is not long enough to stretch down the page, the “container” (as I”ll call it from using MT, I mean the maroon area in this case, where the white courier text of the post itself appears) ends early, and all the images and such that should appear with the main body of the blog behind them float in the air—no (maroon post area) background. (Or in this case, against the brick “wall.”) This probably is much clearer once you see the actual page, its hard to describe.

I’ve tried moving some div tags around…hesitantly, and I’ve tried plugging in some other elements (such as my index page was missing part of the whole “sorry no posts matched your criteria” part of the php “endif” phrase) but I have no idea how to fix this problem.

Here is my (pastebinned) index.php page.

I know its probably a mess in a few areas, I’m feeling that this theme was thrown together (I had to add an entire section to the stylesheet so far, among other things), but if anyone can offer a fix to this particular issue, I’d really appreciate it. Sorry for the long explanation here. If you don’t understand what I”m asking, please prod with more questions. All feedback welcome.