I made a booking through ebookers, using a combined BritishAirways/AmericanAirlines flight (BA for one way, AA for return) about 4 weeks ago. I got booking numbers for both BA and AA from ebookers.
The booking number for AA works on the AA website, and the AA booking shows both legs of the journey, but doesn't allow me to check in on the BA flight.
The problem is, the flight is tomorrow and the booking number for BA seems to be unknown by the BA online system, which is worrying (no, the booking number isn't NOSYNC). The flight is from ZRH to the United States. I do have an approved ESTA.
Is there anything I should do to avoid possible issues, other than showing up at the airport 2 hours before departure? I'm also thinking of US specific issues such as API (AdvancedPassengerInformation) data.