If you click on a forum say:
Penny Arcade Forums » On-Topic Forums » Games and Technology
Penny Arcade Forums » On-Topic Forums
would be hyperlinked.
On-Topic Forums is not hyperlinked, so you can't navigate to On-Topic Forums. It's kind of annoying, maybe it's my account that's messed up. I have to think this is a bug though, since it doesn't make sense to hyperlink Penny Arcade Forums and not On-Topic Forums.