I've noticed this a few times. Sometimes when I post a message in a thread, when it should appear at the top of a new page, it's hidden and there's no link to the new page. It only appears when somebody else replies and there are two posts on that page. This has happened a few times in the past, and again just now in the Custlemm list game.
Any ideas? Andi, do you know what might be be causing it?