Wait... I think I got it... The "Mark All Read" link does contain a sort of time stamp (it is shown by my browser), but I guess it is calculated for each page and not "copied" to the next page. If I spend a long time with the first page and then press it, there is a chance that some new posts were in between that are shown afterwards - but if I check all pages until the last one, this will rarely happen because I spend only little time on the last page. If this is true, then the best strategy would be: - open the first page - open a new window for the second page - view all pages in the second window, leave the first window/page alone - view further pages in the second window - close the second window after the final page - hit "Mark All Read" in the first window/page This way it uses the old time stamp of my initial entrance. Right?