Larry, Is there perhaps a change you made that caused them to be marked for re-publishing - a key wording change or some other minor change you did to a number of photos that included these? I find this with my own work flow at times, and simply hit "Re-Publish". No harm done.
Terry, quite by accident I realized I had uploaded photos to my website with an incorrect
copyright year on the watermark. Though I always update my standard export watermark on the 1st of every new year, I didn’t realize that the SmugMug plugin requires a separate
watermark update. Correcting the mistake was easy enough. Ironically, the photos in the gallery which contained the ‘Modified to Re-Publish’ photos (referred to in my initial post) were actually correctly
watermarked! Go figure. In any case, thanks to John’s information, everything is now as it should be!