I noticed this awhile back, but I always assumed it was some unavoidable system-wide artifact of the forums upgrade. I just noticed that it’s only here, though: there’s an extra level of navigation showing at the top of this forum.
edit: nevermind. I’m not sure what I’ve been smoking. I’d swear I was in another forum just now and didn’t see it :P
but there they are, in every one. It’s only hidden if you click the root “forums” link, but reappears once you make a selection. Oh well.