The Admin log just has a list of the ten or so threads that were merged - including the missing one. It does not actually say where these threads were merged to. The missing thread was merged according to the log but the log does not show where it was merged to.
The mod says he cut and paste the post number to merge to so he thinks he likely did not make a mistake. I did change mysql configuration so I can search 3 character terms and still can't find the missing posts.
