Checking in my wife and me in two separate browser windows, as I have done many times before, hers went straight to the pre-assigned seat but mine showed this message after confirming my name and card number:

The booking we have found from the information provided does not match your Login details. We are unable to check you in online for your flight. Please proceed to the airport for check in

We are on the same reservation. I made the booking using our EC account numbers, oh and my miles. I logged in using the username and password I have used for yonks. For once, I admit to being stumped.

Can anybody throw any light on this? Thanks in advance.