I've been meaning to loosen this up for a while, but only got around to it tonight.
As of right now, the restriction on double posting is removed - so if you have the last post in a thread but later have some need to reply to yourself, the board won't stop you from tacking on that next post. (WE may still stop you... retroactively, later, so - you know - don't be an idiot.)
This was mostly done because I got tired of resetting threads for people who had perfectly valid reasons for multiple posting, so don't worry, it's all to make MY life easier and not yours. Seriously, it's a wonder I keep anybody around at all with this attitude of mine.
(Of course, if it turns out I messed up the coding and it *still* doesn't work for you, let us know.)
It has to be the most recent post in the forum to do it. So, if you are reading from the bottom up, and using the next thread option to navigate, when there is not a next thread to go to you get the mark forum read option.