BillByrd:
Problem solved! Something about the knock-off boards is different in a way that allowed all my other exercises to work while the temp sensors won't. Hope this helps someone.
You could be onto something, but rather than "knockoff" boards being different, maybe you just got lucky - at last.
It might be worth your while to investigate what is really going on. You could start by looking into the meaning of "knockoff" and how it applies in the open architecture (more buzzwords) world of Arduino.