Well, I got a confirmation by email that my bank has accepted the transfer, even as the webpage gave "502 Bad Gateway" at the end of the payment. So I belive it worked...

Also, same thing with the registration mail I got, the confirmation page shows an error but I can still log in and see my details so I think it worked in the end

Propably there's so great an inrush at åpreordering that the system kneels