I flew HKG-PEK-HKG on KA yesterday. There was no record of me being booked on the flight when I tried to check in at the airport. Luckily I had my eticket with me and they located me and then reinstated the booking. However, by then someone else had been checked in and given my selected seat. The return leg, however, had no problems. I think I would have struggled without my eticket number though, so take it with you until things calm down.