Many years ago, with the original photo.net v1.0, I sometimes noticed, that a photo didn't show up in the top rated photos, although it had lots of comments or if it had been viewed many times. Back then, I noticed that if I changed the category, it might then show up in the top rated, so I thought there was some kind of bug, some of the categories were not able to show up in the top rated photos. I guess there might be similiar thing with the new version, too.