New Posts icon stuck in past

The new forums are super zippy, but there's a problem which you might already be aware of.

The icon next to each thread to show there are new posts is highlighting old threads going back to about the 13th - even though I was last in on the 17th. Likewise, if you click "View First Unread", it's taking you to an older post. It looks like something isn't ticking over properly when you visit.

Try hitting the "mark all forums read" link at the bottom of the index page.

Ah - Cool, I'll use this from now on.

Actually, it's not as bad as I thought, because I think it's only threads I haven't visited which don't update, which is arguably an improvement on the old functionality.