Please refresh my memory-- regardless of whether you buy from the attendant or the machine, a credit card can be swiped onl y 2 times before it is shut down for futher purchases? If I want to buy more than two, I need cash or second credit card? Couldn't find anything explaining this on MTA's site. . . . There's 5 of us traveling this weekend and I seem to remember having similar trouble when purchasing passes for a large group who traveled this past summer. . . Thx for the help.