> > I have just realised that when I try to refresh the Recent messages page, the ad at the top refreshes, but not the main part of the page.
>
> I can't off-hand think of a way that would be possible. Are you absolutely *sure* the main part of the page doesn't refresh? The lack of a "blink" doesn't indicate that it isn't; with fast enough connections, most modern browsers don't "blink" at all when loading a new page. The test, I suppose, is to open up two browser windows on the recent messages page, post a new message in one of them, then refresh the other and see if the new post shows up.
>
> If this isn't it, I guess my next question is, *is* there a "blink" when the page reloads, such that the problem is that you just get the old version of the page loaded a second time, or is there no visible change to the page at all?

Generally it blinks as the banner ad refreshes and reappears, but the main part of the page doesn't visibly change. This is when I *know* there are maybe twenty new messages after the ones I can see, because I've seen them on the work computer (from which I'm posting this). When I post a message, that's it, I can't even see that one. It's as though my browser is stuck on whichever version of any page it was on before I changed to this new connection.