Tempesting Template

For some reason, my main page doesn't show up like the rest of the posts do. In all the posts, and all the archives, the sidebar is where it should be: on the left hand side, next to the post. Yet here, on the main page, it is way down at the bottom, while the post is too far to the left and partially covering the background picture. What's the point having a template if it doesnt' cooperate? What am I doing wrong??