Think you are clever #Outlook2010 ? No #fail

I was answering an email, and got a strange error message (see the first marked area in the image)

 

So I clicked on the message and it brought up an entirely unrelated message, but the key was the subject (also marked).  It seems Outlook looks for all messages with the same subject IRRESPECTIVE of addressees.

 

This attaches to my concerns about Exchange 2010 expressed a while back - http://corylus.blogspot.com/2010/04/why-is-exchange-2010-problem-upgrade.html  It seems to reinforce my concerns that the linked messages are connected by a crude text comparison of the subject, rather than a more sophisticated tracking system.