I just did online checkin and was offered the upgrade from PE to J. I selected it, chose to pay with credit card, and the 'processing' sign was on for a minute and then it sent me back to the main checkin screen.

Now the offer is gone, and I can't do anything to change my seat. I unchecked in and rechecked in, and now my seat shows:
12GPaid upgrade Premium to Business (12G is my original PE seat)

However, I can't find any way to actually move my seat (or even access the seat map) or pay for the seat. Anyone seen this before?