Not sure if this is a legit bug but when I post then go back to the front page, the forum I just posted in will say there are unread posts, however when I go into that forum there are no unread posts. I believe this is caused by the post/topic I just posted and it can get confusing sometimes.
Yeah, there's an explanation for that somewhere in the depths of ttf..
ttf marks a forum as read by you when you access forum.php. so unless you have loaded forum.php since your post in that forum, it will show the forum as having a new post.
this is done because of this possible scenario:
you load forum.php at time=1
you load thread.php at time=3
you reply to the thread at time=5
you load index.php at time=7
if someone posted in a different thread in the same forum at time=4, you need to be notified! if reply.php would have marked the forum as read at time=5 (the solution to your issue), you would not be notified.
a new freshie system should resolve quirks like this in the future.
this is done because of this possible scenario:
you load forum.php at time=1
you load thread.php at time=3
you reply to the thread at time=5
you load index.php at time=7
if someone posted in a different thread in the same forum at time=4, you need to be notified! if reply.php would have marked the forum as read at time=5 (the solution to your issue), you would not be notified.
a new freshie system should resolve quirks like this in the future.