03-25-2008 03:58 AM
03-25-2008 09:16 AM
03-25-2008 09:19 AM
03-28-2008 10:57 PM
This is purely a measure of whether you have actually seen a finished post. When replying, you are returned to the thread, so next time you see the new count it should be zero. For new posts, you are returned to the board view, and you will see that there is a new message since you have not actually seen the post in its finished (posted) version.
In your profile, there is a setting for Show Confirmation Page on a Successful Post. When using that setting, after posting you have the choice to go back to the thread instead of Board View. If you choose to go back to the thread, it will count the message as read.