actually, I think the HPMoR comments don't show up in recent comments unless you're already looking at an HPMoR thread... Is it just some setting I randomly edited on my profile and don't remember editing?
“Recent comments” shows recent comments on Main if you're on Main and recent comments on Discussion if you're on discussion.
A fun comic about seashells and Bayes' Theorem. http://xkcd.com/1236/