desde la web de xbox , has agregado la cuenta paypal ??
yo tengo asociada mi cuenta paypal con mi tarjeta visa y mi cuenta bancaria.Haber si es por eso
Use PayPal with your Xbox Live account
Want to use your PayPal account as a payment option for Xbox Live? See if you live in a region where this is available, and learn how to do it. For Xbox 360 Entertainment For All Plan subscribers, PayPal, debit cards, and pre-paid cards are not valid payment options.