This is a theory rather than fact so please feel free to disagree in the comments.
One of the most popular posts on Blogstorm is the Beginners Guide to Linkbait but it is the only post on this site that doesn’t rank for the terms in it’s title tag. It clearly has been hit with some kind of Google penalty.
All the links in the comments are nofollow so I can’t believe they are causing the problem. The only outgoing link that could cause the issue was one to http://www.digitalpoint.com/tools/geovisitors/ which is a page that also doesn’t rank for it’s own name despite having 5 million incoming links.
I’ve removed the link and will keep you updated.