I think the Original Poster is saying that s/he doesn't get any US Dividend Miles; nither Preferred Qualifying Status miles nor Redeemable Miles for awards. Buys on US Airways, it's a United-operated codeshare bought with a US flight#, US Dividend Miles is in the reservation, but doesn't get anything.

Here's likely why: United is flying the plane (or United Express subcontractor is, either case it's United's computer system managing the whole thing.) United needs to have your Dividend Miles number. It means absolutelly ZERO that US Airways has your number in the reservation and you see it when you check your reservation pre-flight at usairways.com. Because if it isn't in the United Airlines computer system, United will never report to US Airways that you took the flight and here's some pennies from United to US to buy the US Airways miles you deserve.

You 100% are entitled to get the miles. But given the realities of the crummy United computer system, and even ignoring that, the usually crummy inter-airline messaging between their systems involving properly passing the FF#, you need always to make sure the OPERATING Airline for each segment of the flight propertly has your preferred airine FF# in THEIR COPY of the reservation.

If you don't see your US FF# on the United boarding pass, you're not getting miles.

At check-in, or probably before, you may be able to find the reservation on the united.com site and add your US Dividend Miles number if it's not in the reservation already.

For the flights you didn't get credit for that you already took, send the e-ticket receipts and boarding passes to Dividend Miles following whatever process US has for claiming missing miles. Maybe there's an online claim for UA. Pre-UA/CO merger, the old UA system allowed the reverse situation (claim UA MP miles for flights on US that weren't credited) online. So US might have hooks back to United for automatically claiming yours. But maybe not, because the United computer system now is really Continental with a name change, old UA systems shut down since last March. You may have to do it by mail.

If you don't still have the boarding passes, shame on you (joking). A real FTer never throws out the BP until the miles credit; it's normally impossible to get them without the actual boarding pass,

Good luck getting the credit, and be sure to check the operating airline's own system in the future before you get on the plane. Never trust Airline A to get your FF# to Airline B.