Yes...Seems everyone has a similar problem. Trying to book 2 tickets from Madrid to San Sebastian for April. Price for each ticket is 21.90E and when I go to purchase them with 3 different cards, I get an error message. Amex, & 2 different Mastercards. What am I doing wrong? What can I do to make it work? Thanks for any help. The step by step guides I found while Googling provided no helpful explanations.