You're browsing the GameFAQs Message Boards as a guest. Sign Up for free (or Log In if you already have an account) to be able to post messages, change how messages are displayed, and view media in posts.
What cards password are you trying to enter? Not all Stardust Overdrive cards are in the game so you may be trying to enter the password for a card that is not in the game. Also, some Stardust Overdrive cards that are in the game cannot be gotten from using passwords like Majestic Star Dragon.
Never assume anything, Assumption is the mother of all **** ups.