I do it differently than that. I don't know if this might help, but I always click on "

New Posts " at the top of the main page. It shows all posts since my last visit. That parameter, found on the resulting page right under the heading "
New Posts" is very changeable too, from minutes ago to weeks ago. The unread posts are highlighted so you will always know which ones are new, unread.
Additionally I keep the New Posts window intact. On the yellow arrow at the far right of each thread, I right click and open in a new tab. It sends me to the last post in that thread. When I close the tab, I can again see the original New Posts list.
Hope this helps.
Aloha,
Mark