Yesterday I was upgraded 5 days in advance for my out flight but was not upgraded electronically for the return. I checked in for the return flight at the PC in IAH before the flight that I was leaving on at about 7:30 a.m. My return flight would leave DFW to IAH at 6:50 p.m. I was told that there were about 5 seats in FC available but they had not been released. I was also told I was number 1 on the list. At DFW that evening (about 6:00 p.m.) I checked at the PC and was told the seats had not been released, but there were now 3 available and I was still number 1 on the list. She told me to check at the gate before boarding.

At the gate at about 25 minutes before departure I asked the gate agent. She said that there was now only 1 seat available, to go ahead and board, that I was probably not going to set upgraded, that now I was number 3 on the list. I boarded, and right before the doors closed they upgraded me.

I was also told at the DFW PC that the upgrade list plat, gold, then silver, and that the fare you paid did not matter.

I am a plat and I was on a V fare.

This was a very short flight DFW-IAH - maybe 40 minutes in the air, but in the afternoon I like FC because at least you can have one drink to unwind after a long day, sometimes 2 if the FA is quick. Either way I was not that concerned about the upgrade but I am curious as to the mysterious procedures of the upgrade list. I am also assuming that they did not sell the 4 FC seats on the day of travel and I doubt that anyone would pay the $600 one way fare to fly on FC for 40 minutes, and at that time of night there is only the BF flights to South America as far as people connecting.

My questions is (1)is there really a list, and how did I move from 1 to 3 if I checked in first and I am plat; and (2) where did the other four seats go? IE how does this work?