Paxing up from Hong Kong to Beijing with Cathay to pick up my aircraft (corporate jet) and fly back. We arrived 2.5 hours early to check in. Cathay told us our visas weren't valid (crew visas) since we weren't arriving as crew of the aircraft we were on. We knew this could be tricky since we needed an Air China handler to meet us in Beijing to explain to customs. It had never been a problem before, only a few minutes delay.
After 2.5 hours of frantic phone calls and faxes of documents we ended up checking in with Dragonair (sister company of Cathay) who couldn't understand what all the fuss was about. We haven't flown with Cathay since.