I'm hoping that someone here can confirm this is stupid and that I'm being fobbed off by the BA call centre. But I'm not holding out too much hope. It sounds like just the sort of stupid thing that they would do. I have a LHR-ATL-ORD-LHR round trip booked with BA. The ATL-ORD leg is with AA the other 2 legs are BA. The trip was booked through my work travel agent not with the airline directly. I am trying to upgrade the LHR-ATL leg with Avios but the call centre are telling me that I can't because of the existence of the AA leg on the booking. The website says that there is availability on the flight so it isn't that. Is that really true? Has anyone else experienced this? Did you manage to get around it?