I've searched and can't find any posts mentioning this situation. I am Premier Gold. I am flying DEN-GEG with my GM Daughter tonight. For the past few days, there have been 11/12 seats booked in F. I told my daughter we had no chance of being upgraded. However, when I went to check in last night, we both had been upgraded. Mind you, there is only one seat available in F. I assigned the only open seat to her. I no longer have my excellent aisle seat in E+ Exit Row and I don't have a seat in F. My boarding pass says "See Agent" where the seat assignment would be. I called United and the agent confirmed there were no seats left in F, but since there were plenty of seats still left in coach, she suggested I not downgrade myself. She seemed befuddled...and first said, "I wonder how they'll handle this at the airport" and then said, "Revenue management must know something we agents can't see". This morning, F shows booked full; economy still has seats available. On the upgrade list there are 10 pax with seat assignments; 7 checked in; 4 on the wait list and I don't show up anywhere! Very unnerving to say the least. I'm less concerned about getting the upgrade than I am about sitting in a middle seat in E-!Will be interesting to see what happens at the airport. Any one else have this happen?