Hi Jonathan I don't know if it is something on my PC or the forum but I am sometimes not seeing some posts. I also sometimes see posts that seem to be awaiting admin approval so it may be linked to that.
A classic example is in thread http://www.ballroomdancers.com/Message_Board/view_messages.asp?Action=open_topic&Topic=47304 where voco appears to be having a conversation by himself. I'm guessing there should be some posts by OZ but I cannot see them.
I looked into the thread you mentioned, to make sure everything looks kosher. I didn't find anything that would indicate a problem with the code, or evidence of hacking or anything like that. It does look like half a conversation, however, so my best guess is that the missing messages belonged to a user who decided to delete them later. I remember putting a time limit on editing and deleting one's own messages, although I can't remember what it is off the top of my head. Whatever it is, apparently he made it in time.