Subsequent to my above posting I downloaded all the Post Views Counter files, and then did a search of all of them for the old IP Address. It did NOT reveal any reference to it. Very perplexing … Apparently one of the PVC files refers to some other Word Press file that contains the old IP Address. I wonder which one?

I then today Deactivated PVC and then Deleted it; I hoped this would somehow remove the erroneous reference. I then reinstalled PVC, and then went to the General page and tested the results by clicking on the “Add My Current IP” button under “Exclude IPs”; it returned the old IP address. The deletion and reinstall then did not resolve the problem.

I wonder if clicking the box for Deactivation that recites “Enable to delete all plugin data on deactivation.”, and then trying Deactivation -> Delete -> Install would resolve the problem?