anyone used marketplace on ebay yet rather than paypal?

i completed the checkout part of the payment to a seller, but when i got to the paypal stage to select the card for the payment to come from i realised the card still wasn't active. so had to log out. now, when i try to go back in, i can't make the payment - i'm being told 'these items are currently being processed in another order so cannot make payment'

what do i do? can paypal be used to send the money to the seller directly rather than through ebay?