Originally Posted by
Mike Jacoubowsky
So then maybe I'd better book the non-existant flight on the US Air code share to lock in the pretty darned low price while I can? And then fix whatever I have to fix later? Strange...

You can always cancel in the next 24 hrs. But to change to a UA flight number you will need to cancel. Codeshares are a pain for upgrades.
The availability problem I have been seeing is corrected the next morning.