"My next test will be disconnecting the wire from the Pin to see if that helps. If it does I have to suspect that the pin "socket" is damaged (hence, my thought about cleaning the connectin holes).."
Removing the write from the pin did not help. I also tried rebuilding the hardware on a new UNO R3; the same problem occurred!
BUT, I "tore down" the board and UNO wiring and re-built it. I also stripped down the sketch; thus far, the problem has not re-occurred!. SO, this might be solved. More to come after I add more of the steps I want in a now stripped-down" sketch.