If you are preparing to post a reply, and someone has posted since you started writing it, the forum will alert you to this fact, and show you the new post(s) in question that appeared - so you can modify your post if need be.
This isn't a bug, it's a regular thing. If you're referring to this post:
Damnit DragoBoy! I was just going to say that. But since we posted simuteneausly (I know. I butchered the spelling.), one didnt go through. We all know whos it is.
S.S. Royal Unova, S.S. Anne, and S.S. Agua.
I can see it just fine.