Boy, I'm glad I'm not the only one that's having this weird problem.
My error message is EXACTLY the same as Horseshoe. It has been this way since way back when I first posted the problem. It has never changed.
I flashed the Firmware on both drives:
740a from 1.01 to 1.02
716a from 1.08 to 1.09
... restarted to desktop both times.
No change in errors.
Where's my scotch