I suggest changing the number that stands near the sub-forum's name from the total number of posts to the total number of topics. I'm pretty sure that I'm not the only person confused about this. It can also show both topics and posts, as an alternative. The way it currently is is confusing.
Take the "Announcements & Information" sub-forum, for example. At this very moment, the number shows "357 posts" but upon clicking it, the sub-forum only contains a bunch of topics.