We had an inter-Europe flight this summer, showed up to the airport just before the baggage cutoff and couldn't figure out why the kiosk couldn't find our reservation. Went to the counter, still couldn't figure it out. Lo and behold I finally saw on the BP (that I had printed out at home a month earlier) that I had booked us for May instead of June!!! It was a once/week flight and now it was too late to check bags so we had to take a connection instead for 3x the price and made it to the wedding just as the ceremony began.