My WordPress theme BinaryBlue has a feature to show the comments in a paged way, so the serverload would be less than when displaying all comments everytime. Looking at my Google sitemap stats, I saw that most URLs (if not all) that resulted in a 404 contained “comment-page-1”.
So I viewed the weblog, opened an entry with comments and looked at all the links on that page. The URLs pointing to the individual comments all have something like “comment-page-1” in them. But clicking on them will give you a 404! So I went back to the administration panel and went into the BinaryBlue options, since that’s the theme I’m using (WordPress does not have paged-comments by default, you have to install a plugin for that). I disabled the AJAX-paged-comments, and voila….it works. No more dead-links.