Originally Posted by anabolism

I don't think this is specific to QR, or that QR has anything against certain flyers. My guess is that it's a glitch stemming from an itinerary booked and ticketed in one GDS (such as Sabre, used by AA) not correctly propagating ticket numbers to a separate GDS (such as Amadeus, used by QR, QF, CX, BA, etc.) used by the airline operating the flights. I've had this happen on AA-issued xONEx with QF flights. In my experience, the most likely trigger is when a change is made, causing the tickets to be reissued, and the new ticket numbers don't get correctly transmitted to the operating airline's system.

If you want to be extra-safe, after an itinerary is ticketed or a change is made and the tickets are reissued, call any airlines with flights on the booking and ask them to verify that they see the itinerary as ticketed. If they do, you are fine. If they don't, call the issuing airline and have them resend the ticket numbers.