Notifications for things I've already been notified about

This has been happening every so often, and it happened just now. I got a new notification for an old comment/mention/post from almost a month ago. Nothing new added to the comment/post.

And I guess while I'm here, this an issue for a while. When I get a bunch of notifications, I like to check each one individually. If someone mentions my username in a comment -- "@zork" -- I get TWO notifications for that one comment: one for the fact that someone's replied to me, and one for the fact that my name was mentioned. It'd be nice if I could just get one notification for each comment.