Just called Amex Online Help Desk in the UK. Actually, quite a nice friendly service (unlike these BOI Card Services people who just say "We don't do it, that's it, anything else I can do for you? No? Bye!"). The guy from Amex called BOI, then some other croud in the UK and unfortunately online registration is not working with BOI. They promissed to fix this about two years ago, but it's still under development. Basically, it's up tro BOI to provide with AmEx online service that they don't bother doing for years.