I recently installed the Twenty Twelve theme and created a child theme for customizations. I replaced the default site title that appears at the top of the page with an image by adding an IMG tag to the header.php (just above the HGROUP tag) per the suggestion in another forum topic.
The problem is that the sidebar/widget that normally would appear in column to the right of the content has been pushed to the bottom of the page, below the content. At first I thought it was because I was using the full-width page template but that is not the case. It happens on the front page as well as all post pages.
Could the header image (960px wide as recommended) be forcing the responsive design to use a full-width layout? Yes, I'm seeing this layout issue with a full-screen browser on a big monitor.
You can see the site at http://www.parentingmd.com
Thanks in advance for any suggestions.