I think that's what happens when dang "bumps" submission which was considered interesting but overlooked, but I don't know how exactly that process works, he probably explained it in comments somewhere.
Thanks - it's kind of weird that it screws up the date, though.
Edit: actually, I have a guess. Maybe the moderators don't have access to the algorithm and it isn't that flexible, so the way they hack around it is by changing what the algorithm sees as the posted date of the submission. If the algorithm thinks the submission was made more recently than it actually was, it will bring it back to the front page because the score goes up.
