this has come up a few times at work and our TA explained what was happening. and u can try the same thing by going to the US sur and trying to book something after 10/16 where u will be directed to the AA site to book the whole thing....or on the US site, look at an itinerary before 10/17 and then change u dates a flight request after 10/16.....

so whats happening is concur is displaying fare, say round trip, but is looking at the availability one way at a time. What we were told was that it will let you book the outbound say as a US prime or codeshare....but when it tries for the return, it is getting the equivalent of the US airways site message that this itinerary must be booked on AA.com and with an AA prime flight number.

we did a few tests and had our TA duplicate to see what she was seeing.....basically the net is that Concur is getting a must book AA prime (after 10/16) from the underlying GSD and concur is translating this as an error and will then display all AA prime flights for the itinerary.