Well, today I made the happy discovery that as long as the *only* thing you change in your B&N payment info is to update the credit card expiry on your default, then the system sticks with using the old keygen method for books downloaded after that.
So if anyone's been having problems using the workaround new key-getting method and haven't changed their B&N account info otherwise, then maybe this could be of use to them.
I also made the unhappy discovery that the B&N UK site doesn't actually let you update your CC info
in situ, and does a delete/replace which puts you on the new DRM key-generating system.
In retrospect, I should have logged into the UK account via the main site and then updated the CC expiry date from there.
That said, from then on if you make any further changes, such as modifying your billing address name (which does change the key again), and then changing it back, you do go back to using the "old" new key from before you made said minor changes after you've reverted, so there is some consistency in how the new version works. Hopefully someone will be able to figure it out.
