You can make a post using the "Quick Reply" section and post it, all without the page reloading (it may look like it reloads, but it doesn't)... That will cause the "issue".
Edit: It just happened to me too. But once I actually refreshed the page, the time updated. When you use the quick reply, or even edit a post within the page it does not reload the page. AJAX ftw/ftl.
Edit: It just happened to me too. But once I actually refreshed the page, the time updated. When you use the quick reply, or even edit a post within the page it does not reload the page. AJAX ftw/ftl.