you didn't maybe click Mastercard instead of Visa by mistake or something? Can't think why else they'd mix the cards up like that. Visa have a Verified by Visa setup as Chris says; I don't know what hte Mastercard equivalent is.
jno dont know what has happended! Went on the link to capital one (visa) to register my card for this secure code thing but I put my card in loads of times and it says it the incorrect card number! I'll have to phone them tomorrow!
I meant the original demand for a Mastercard secure code - I thought maybe when you first clicked to pay you'd ticked the wrong box or something... I'm baffled too.