This is just a thought, it's not too big a deal.
If you look through a forum at all the new posts, then you go to the main index, it shows no new posts for that forum (little paper thing is grey instead of blue), but if you look at all the new posts, then post something yourself, and then go to the main index, it shows a new post (thing is blue), but that new post is yours. Is there a way for the site to recognize the post as yours and not tell you there's a new post there, so that you don't go back into the forum looking for a new post only to find that it was only you?