This is interesting. This has never happened to me or have I ever heard of this. Interesting story about something like this that happened to me about six months ago. I was scheduled to return from LAS to ORD through LAX. I called earlier in the week to see if I could get on the non-stop. They said absolutely not - I had a special fare through LAX (I forget the technical name) and that I wasn't allowed to go on a non-stop, even though there were seats available in my class of service! Well, I used the old rule of calling back and talking to ther agents (1K, 1P desks) to no avail. Must have called a dozen times; they were not going to change my flight. Get to the airport on Sunday, the LAS-LAX flight was way oversold. I volunteered, they used my seat, got $400, and was put on the non-stop flight that I tried to get all week. Gotta love United! Thank you for paying me to get on the flight I originally wanted.