Safemode is indeed a useful "crutch", at least often lets you get something critical done, but as you say can be very tough and time-consuming to pinpoint these types of things.
My problem is at least temporarily solved, although I will not be too surprised if it re-emerges after an update of Turbotax or two.
My two systems being completely different, very little software or setup overlap, but each exhibiting the issues, makes me suspect something more fundamental in Turbotax's internal call structure to process state info.
Fortunately, I can now move on to what I was actually trying to get done - some tax returns!
Again, thanks, your inputs really were instrumental in moving me in the right direction.
