Shopify/active_merchant — pull request #836 by larspind (2013-09-10 19:20:52+00:00)
Title: Fix that referring to a card token no longer worked

When using the card token option, you have to submit a string value for the card, like card=tok_XXX, rather than card[number]=tok_XXX, otherwise it takes it as the literal card number, which obviously fails, because tok_XXX is not a valid card number.