My wife and I were on one PNR and my son and his wife on another. They checked in and headed for the gate. My wife and I were behind them in line and got the next available agent, about 5 agents down from my son & dil. At boarding I went last and my BP beeped the system. GA said that it showed I'd already boarded. Looking at my BP I realized I had my son's. They got him off the bus and he had his. GA found all records in system and it indicated that 'I' had never checked in (and my seat had subsequently been given away). Someone the agent managed to check in my wife and then instead of checking me in (on the same PNR as my wife), checked me in as my son.

Not only did the AF agent screw up in giving me a BP that didn't match my PP, but nobody in security caught it either.