Yippie-Skippie! Thank you Warren.
I did as you suggested and it worked!

Previously, I had replaced the save file with a copy of the backup, figuring that the deleting was happening as part of that process. This time I deleted the files as you said and then copied the backups into the then empty folder. I should have thought of that in the first place, I guess.

I'll just never understand how a file can be just fine and great one moment and corrupted the next. I used to blame it on gremlins.... but now I guess I'll have to blame the little villagers running loose in my computer. ;\)

Anyway, thanks a million!