>This is exactly what this option is about. If you click on the icon, it is as is you were entering the forum. Which means, you'll get all new messages. Of course, don't click on it, if you haven't finished reading the new ones which are already shown on the upper right frame. However, if you want to get new messages without refreshing those, just click on the link under the icon instead. You'll then get them in the lower right frame.

Thanks a lot, I hadn't noticed I'd gone from clicking on the number to clicking on the icon.