I'm having the exact same problem as the original poster. Website unable to retrieve my reservation after a schedule change. I also called Copa and they also said booking was fine. Tried to access it through the mobile site but didn't work either. Called them just now and requested to have my itinerary emailed to me. I gave them two different email addresses and so far I still haven't got any email. Check my trip is showing booking confirmed, that's the only reason I'm confident the booking is still ok.