I have the exact same issue. It worked fine in 4.6.6. Windows XP machine.
Neither the ingest nor the 'open as contact sheet' settings work when windows automatically opens PM. However, they do work when PM is already open and THEN the card is inserted into the card reader.
Windows works as it always did -- insert the card and it opens PM automatically. But PM no longer behaves the way it used to.
When I did an successful ingest while PM was opened, a .pmingest.dat file was created. I then removed the card, closed PM, and reinserted the card. Still no joy.
Regards,
Frank