You may notice that all the threads are not marks as NOT READ. I have changed the way the site keeps track with which threads you have read or have not read.
The default way was "Inactivity/Cookie based".
I have changed it to "Database (No automatic forum marking).
In other words when you have a lot of new messages to read they won't mysteriously DISAPPEAR!!!
You can mark all forum posts read via the link at the bottom of the main forum page.