Div’s drop on post page when user not logged in

http://www.revomediaonline.com/blog

My sidebars drop below the content on the post pages when comments are closed or a user is not logged in.

Here is a direct link to an example:
http://www.revomediaonline.com/blog/2008/02/14/terrapins-fall-to-duke-yet-again-77-65/

Any help would be greatly appreciated.