Will do, Bill! I've managed to refine my search on Google and have found that though this is not common, it's not uncommon either. Unfortunately, none of the folks with these occurrences have come back to their blogs and given a reason for the problem. Maybe they just decided to cull the chicken? My first problem will be to find out which chicken is laying the bad eggs. It would be easier if they all used separate boxes, but they like the community approach, it seems!
I did find two other posts where the chickens laying bad eggs were free range, so there was a great deal of "unknown" in what was being consumed. Possibility of fungal or bacterial infection. I do have one hen, Stephanie, that has figured out how to escape the coup. She's named after Stephanie Plum for her entertainment factor and ability to escape captivity against all odds. That gives me a 2nd suspect, in addition to the old hen, for a place to start.
Anyway, I have the old hen locked up in the horse stall for the weekend. IF I can catch Stephanie, she'll go in there, too. Hopefully, it will be one of the two.
The search goes on....