Margin Problem/Missing Sidebar Nav

I have a problem with a very wide left margin that only appears on ‘post’ pages (ie. when you click on a post on the homepage and it opens in its own page). Also – there is no nav in the sidebar on theses pages (both are fine on the homepage and ‘page’ pages though. Any tips/pointers would be greatly apreciated.

The problem looks like this
http://www.bmdd.net/test/professor/index.php/2006/07/03/cocktail-of-the-week/

The rest of the site is fine
http://www.bmdd.net/test/professor/