User blog comment:DaNASCAT/Technical Update: April 3, 2012/@comment-3202289-20120403192131/@comment-3030984-20120403194513

I think it's just a limit of MediaWiki. As far I as I understand it (i.e. I made it up), internal links are designed so that they take you to the page with the title which matches your link, not the page with the url which matches your link.