The "View First Unread Thread" is useful but it disappears while viewing the forums and then I can't get it back. I've tried logging off/on, clearing cookies, clearing cache, clearing history, shutting down all browsers, shutting down my laptop and finally cursing. When I log on, I click the "Remember Me" button. Once the "View Unread Thread" is gone, it's gone until the next day or some future time.

Any ideas about why it disappears and how to get it back once it's gone?
(Win 7, Firefox 29.0)