I am flying from IAH to SFO today with a companion on the same record locater. I upgraded the tickets (not the cheap fare bucket either) in March, and CO withdrew the miles expeditiously from my account, however, placed us both on a upgrade waiting list (2 seats sold in FC at the time of upgrading). Yesterday, I noticed at check-in that I had been upgraded, however, my traveling companion had not. After 40 minutes on the Elite line (Yes, that wonderful dedicated line that no longer has agents to work it), I was told that the computer split the reservation automatically, and only upgraded myself (though, we are both Plats), and at that time, there were no more first class seats available (others had been upgraded). The agent said that this should not have happened, however, CO has taken away much of their control of the system, hence there was very little they could do other than move me back to coach (which I did). As a warning, if you are traveling with your wife, business partner, significant other, etc. watch the automatic upgrade system. Great way to reward loyalty!

PS - I asked someone from CO to call me and explain to me why their system was configured this way. I'm still waiting for a response.