At the top of the forum's Board Index page there is a message that tells you when you last visited the forum. In my case it seems to be stuck at Last visit was: 28 September 2012 22:54GMT. I generally check the forum pretty much every day, so I have visited the forum and posted messages several times since then. The date and time looks like it might be my last visit before the recent updates were rolled out.
It's not a big deal, though. Features like "unread posts" work they way they are supposed to.
マイケル
