This is part of the core of HN. As I understand it, it generates those links on the fly, and they expire. I think they are handled by some sort of lisp callbacks that expire at a certain age. It's not something that can be fixed with re-theme-ing the frontpage.
Right, but complaining about it to someone that spent a small bit of free time reworking the frontpage for fun seems out of place. He probably doesn't have the skills or access to make the changes that you want.
