Well, here's my latest bug report. I went to visit my brother, who lives about two hours away, today. I knew he had a SNES so I brought along my PowerPak. When I tried it on his SNES it gave me the exact same errors as on a SNES jr. His is a full size SNES, rev 2/1/3 with the molded eject button.
That was a bit disapointing since the powerpak is supposed to be compatible with all full size SNES consoles. I may email this issue in to Retrozone, though I suspect it won't be fixed until the SNES jr issue is fixed.
Mitch