Passport Validity, having trouble buying flight tickets

Hello, we are leaving for China Monday and are to be arriving October 28, 2015 in PRC leaving November 13. Our passports are to expire April 5, 2016. Our visas are multiple entry and do not expire until 2024. I was trying to process our check in with the Airline and it was say our passports are not within validity. So I could not process our tickets. Does the Airline determine if we can travel with less than 6 months on our passports? Or if the airline allows us to travel with our passports will we have any issues getting into PRC with less than 6 months on our passport?