Thanks! The new flight is on "Mesa". Never heard of them. So I guess that's the hold up? It's not really United. One of the other flights on the six (three there and three back) changed by nearly 90 minutes so I guess I have a good case? I will see about flying into IAD the night before. Luckily the airport hotels around there look pretty cheap, compared to Boston and Chicago. Appreciate the advice! It did just seem kind of strange. And yes, I did try several times to change it on my own. I put myself in the seat, got the yellow little circle, and all looked good but the itinerary still had the old seat. Never did get it to 'stick'. Did not get an error message or the ones you get from trying to change your seat for LH on a UA ticket. And neither explanations from the phone reps made much sense. THANKS MUCH!