Heh, try not to worry too much. It generally takes about a week after the NCIP's (New Cat Insertion Protocols) for cats to figure out their New World Order.

If it's any consolation, it took the better part of a year for my three cats to get used to Smudge (the fourth), but only about three days for George and Pan-Pan to get used to Gretzky. So your mileage may vary considerably depending on the cat.