You're using a WP theme. On basically every WP theme that I have worked on, the home page uses an h1 tag for the site title. On other pages, it uses another tag and reserves the h1 tag for the post/page title. The h1 tag has margins around it, which is pushing your content down for the home page.
So...add this to your stylesheet:
Then, you probably have to change your body's bottom position to 37px or so.