Now I care - accidentally closed my browser. Opened up browser and this time the list of unread posts was only a few in comparison with three pages previously. I guess it is right though, in that these are unread since my last visit. I generally never close the browser so never have any problems with the unread posts (never turn the computer off, either, unless I have to). Maybe this will help with consideration of this issue.
I would prefer to see all unread posts, rather than just those unread since last visit.
It usually works for me, I always turn my computer off and it still shows the posts I didnt get the chance to read the last time
After reading the Unread Posts, have you ever gone through each section to see if there are any posts that have been missed? 
I have noticed that some of the posts are appearing in their relevant section without a "New" icon next to them, yet they are "unread" posts but do not show up in the Unread Posts list 
Matthew
It used to do that for me, but I haven't noticed it lately, I'll pay a little more attention and see.
