No, we haven't managed to fix this. The new SIM works in my 3g phone but not in my wife's 2G which is what it was for. It just says wrong card and since the card. I understand from the Community that the new SIM only works with unlocked phones but since it has been has now been activated the old card will not let me unlock the phone.
This is the phone my wife has had for sometime with Virgin - you are right the new SIM is not compatible and having switched off our existing SIM, the phone is now locked and unusable - great service! So much for an exciting new experience!!!