Hit the "More Options..." button which takes you to a new page and hit the "Reply to Thread" button there.
Seriously though. What is causing this and why can’t it be fixed? Been going on for close to five months. It’s not that big of a deal, but it does clutter things up a bit.
I'm using Firefox on a Macbook and a Window PC. It's happening on both. My previous comments never get cleared from the comments area even if I move around the BBS. I've learned not to hit Post Reply so I don't double post but it would be nice if my comment would clear after I post a comment.