Web support should be able to manually do the booking for you. You have to replicate the problem with them first then do the following. Tell the IWS agent the exact flight, times, dates, and the fare code basis you want to book. Then have them manually apply the cert, and voila IWS should issue the ticket to you. You might even receive this friendly reminder as I did from the IWS agent, make sure you bring a photo id for your check-in when travelling on a transatlantic international itinerary. Passport, what's that.