I'm trying to cash upgrade one segment of my r/t itinerary. After selecting the leg on which I wish to upgrade, I click all the way through to the "continue to payment" button only to find an error message on the next page. I tried calling the Senator line. The person on the line saw the same upgrade price as I did. But when she tried to put it through, it showed no availability. She then tried to "manually" (whatever that means) do the cash upgrade. Then she could upgrade me, but only at the price of the highest booking class, which was nearly twice what the website offer was (and what she had seen herself). What's going on here? If I try to upgrade any other segment on this itinerary it goes through fine to the payment page. It seems just this particular leg is experiencing "technical difficulties." Anyone had this happen before? How can I get the stated cash upgrade price?