Oh my gosh — you did it! That one little thing and I spent an hour talking to a nice young many in India who couldn’t help me in the long run. I’ll report back tomorrow, but the black is gone. It was a weird day on the computer. Many thanks.
Regarding: Mac OS X Snow Leopard corrupt color profile resulting from attempt to custom calibrate display using Spyder calibration software and hardware. Resolution involved removal of all custom profiles in Macintosh HD->Library->ColorSync->Profiles, permitting system to default to a functional color profile.