>Opera shows me more details than IE, with respect to what is going on; and I was wondering about the following. When clicking on the button to fetch new messages, when there are no messages, the data transfer used to be some 13 or 14 KB; now, it went up to 30 KB. Nothing serious, really; but I wanted to mention it, just in case.

It depends, among other things, about the banners. Some are bigger than others in regards to their size.