OP here...well, I called Disney Dining and, sure enough, there WAS a credit card attached to my reservation! I was perplexed as to HOW it was there since I DID NOT plug one in at the time of the reservation. After talking it through with the CM she concluded that WDW pulled the card number from my recent resort deposit which was made with the same credit card found on the Be Our Guest reservation! I was pretty surprised that the system found my existing credit card number used for my deposit and used it without asking me if I wanted it put on that card, etc. Oh, well. My ADR is legit and that what matters. Mystery solved!