You might want to make sure your bank hasn't stopped the payment, sometimes this happens if what you're spending is out of the ordinary for your account.
It happened with me when I ordered. Entered card details in twice, and they were rejected. 2 minutes later I had a phonecall from the fraud squad of my bank, just doublechecking that it was me trying to make the transaction.
As rak said, if its a transaction which is 'out of the ordinary' and the pin is not being used, they may stop the payment. If you phone up your bank and tell them it shoul be sorted fairly quickly.
You might want to make sure your bank hasn't stopped the payment, sometimes this happens if what you're spending is out of the ordinary for your account.
Totally right, this happens alot nowadays, you will either get a call from you rbank within a few minutes - or in some cases youll need to contact them yourself to unblock. Try again and it shall now work. (They may say give us 5 minutes or something).