It is actually not a big deal because Orbitz is just passing on the miles that you get when you from US Airways' website.
So, always use the major travel sites for general search and book the flight that you want from the airline's website for bonus miles.
By the way, I never booked from Orbitz as it is always advantageous to book from the airlines' website.

[This message has been edited by empee3 (edited 08-19-2003).]