SW does some strange things but this one is too much.  I am using replace components to replace a component with an assembly containing the same component.  I am using the automatic mate detection.  All the mates show in the replace component dialog box as good (green check).  When I close the dialog box the assembly tree then shows one mate as invalid(red).  I can edit the mate and confirm that in the dialog box everything shows as ok.  When I close the dialog it still shows the mate as bad.  If I hit manual rebuild it still shows as bad. 

Only if I then try to drag the compoent (it of corse won't move since it is fully mated) and after not actually moving will SW regain concousness and the tree suddently mark the swapped component as "needs rebuild and selecting a manual rebuild will it will actally finish solving the mates and show the swap as successfully completed.

This convoluted procedure works, but it is sure is a round about way to get the software to realize the mates are correct as they were indicated to be in the very first dialog box.  I found this sequence by pure luck trying to see what SW thought was the problem since the message given (invalid or suppressed mate element) was obviously wrong.

-Greg