Sidebar floating below main content

http://www.texaspaceauthority.org/for-contractors/ We noticed that the right sidebar is floating below the main content on some of our pages (like the one above). It's odd though, because when I "inspect element" in Chrome or zoom in or out the sidebar returns to its regular spot at the top right of the page. I removed all of the custom CSS I had added to see if that was the solution, but it did nothing. Any ideas on how to fix this? Thanks!