Problems with child site

Hey everyone. We have a site that was built last year. It’s theme is a simple, child-theme based on twentyten. The orginial site was built on WP 2.5. I want to copy that layout, and only change a few things (i.e. the background image & text)

So, I copied the child layout, installed WP 3.5, and installed the duplicate theme. However, after installation and activating the theme, I noticed a bunch of layout problems. The link is: here Can someone point me in the right direction as to why the header is off-center? It almost looks like everything is off center…I’m stumped! Do you think it’s because of WP 3.5?