The invoice address is meant to be their billing details pertaining to their payment method. It's sent along with payment to payment providers. They need to be able to edit it because they could move, change phone numbers, etc.. They shouldn't be able to give false info. Your payment provider should be setup to verify it against their payment method (e.g. AVS verification).
I don't understand what you're trying to do with CB Auto Actions here. As I understood you were synchronizing profile fields. Are you forcing a country for them?
This problem appeared suddenly last week! We did not have such problems before.
Do you recall anything changing in the last week? The only update we released in the last week was for CB Gallery.