You should have a button where you can see all of today's posts and all new posts. Other forums have them, why not here?
There is a link "Show all unread posts since last visit" which does that. What I have done is added a button to my browser bar that follows the following linkhttp://www.happyatheistforum.com/forum/index.php?action=unread;all;start=0
Now if you go to the front page and 'mark all read' and then use the link above you get to see all the threads that have new posts in them.
Hope that helps.
The other thing that you will not be aware of is that a little while ago the forum was transfered from a phpBB database to this SMF one. Some of the older posts have odd non-functioning links in them. In addition the site is owned, funded and run by Whitney and she has a busy full time job so things don't get done as fast as they would on a multi-admin forum where one or more of the admins has time on their hands.