Hey DP,
I think I know what you're referring to. The way this forum marks posts as read isn't as robust as some of the other forums, but from what I've read (and I've read a lot) the reason is to keep server loads down and the forum fast.
A lot of people have requested different "read post" handling features / options at the designer's forum, but he always pushes back because he's worried on how it will impact performance.
I'll keep looking into in DP and see if there is something that can be done while keeping speed up.
BTW, show me exactly what you're referring to so I know what to look for.