On other Xenforo forums I've used (and there have been several), the alerts at the top continually update as long as the window remains open. I've noticed that on this site, this very rarely happens. Often the "Alerts" button has no number on it to show how many alerts there are, but reloading the page reveals that there are alerts there. This seems to happen every time for me. I'm not sure if it's deliberate (to reduce load on the server of all the browsers checking) or if it's a bug somewhere, but I thought I'd report it just in case.