Try posting screenshots of aa.com and usairways.com award searches for your preferred travel dates and maybe the forum can offer more specific trouble-shooting.
Here's what I see on AA, attempting travel from 23 Nov with return on 3 Dec, for example.
And with the same, on US
As you can see, there is much different availability between the two. I appreciate any suggestions you have 3Cforme (and others, of course)!