I've seen that every so often. I just figured it was due to people editing their posts, rather than new posts coming in.
EDIT: Here's an edit. Did that generate a new notification?
Not even one email, but irwin7638's response at 9:25 triggered an email and it's just now 13:50 or so that I'm replying here. Since you posted/edited after his reply but before my next visit to the topic, I wouldn't have received notification of your actions at all: "
There may also be other replies, but you will not receive any more notifications until you visit the forum again."
No biggie at any rate - Just curious.
Thanks.