News flash! While I still think the insides of the scanner are a bit dusty, I finally got the Nikon software to work. Guess what? No more blow-out halo type highlights. At least with the slides I tried. I will have to dig out the Xmas Cactus slide again and give it a whirl.
Vuescan is nice, but I think I need to learn how to control it as it appears to be causing this problem.
I will keep you posted, as I'm sure this is the most intensely interesting thread on the board right now. LOL.