Forum Moderators: open
The Red-dots aren't automatic. You have to use the "Reset Last Read Pointers" option.
You can do this for the whole board [webmasterworld.com] or individual forums.
When inside of a forum, or reading any message in a forum, there is a link in the top right which reads "Reset last read pointers". Click this link, and the red-dots will disappear until new posts.
Cheers,
wruk999