what version of the game do you have? And what game are you reffering to? If its Honey select? Have you looked in your userdata/chara/etc or userdata/chara_old/etc if the cards dont appear in game. They might ended up in this place instead. Wich means the game dont recognize the cards is for the game. This has happend for me sometimes the card downloaded wasnt that said game or even a loadible card.
would help to known what game your having trouble with cards with....