<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by Old Gold:
It's there, and it works!, and wonder of wonders, I was able to select a "Premium" seat on a codeshare flight operated by America's Worst. Praise the Lord!</font>
Hmm, I have an upcoming flight with a couple segments on HP so I tried to change the seat assignments to premium as you did.
When I pulled up the seat map for the flight, and clicked on a HP Premium seat, it looked like the web site was giving it to me. The seat turned black to indicate that it was assigned to me. BUT- when I clicked "Continue" or clicked on another flight, the premium seat assignment didn't "stick", and it reverted back to the original assignment. I didn't get the premium seat. Are you sure this worked for you?