[masraum]

Rick, I think you may have hit the nail on the head. Now I have to find/repair the problem. I did a search on the internet for "hot to ground reversed" and found a forum with this answer to a nearly identical problem description.

Yes you had a bad neutral connection or open due to those backstabbed outlets. These are notorious for this problem. You did the right thing moving the wires to the screws. When you use those outlet testers and the lights tell you that you have a hot/ground reverse this really is a open neutral indication. When you think about it getting the ground and hot connections reversed would be pretty darn hard to do, especially when you had a working circuit and then it stops working and you havent touched a thing. There are some people that think there are little green creatures running around in your wiring messing with you. The reason you get this hot/ground reverse as I understand is that with other loads plugged in to the circuit...lights, battery chargers etc when your neutral opens somewhere in the circuit you can actully read 120 volts from neutral to ground from backfeed through these other loads on the circuit. Your tester sees that voltage and indicates you have a hot/ground reverse. If you unplug all the loads on the circuit and unscrew the light bulbs and prevent this backfeed then the tester will change to an open neutral indication. Does this make sense to you?