Interesting; I'm on UA 223 on Monday; it's a good thing I saw this thread, because the system had moved my seat into one which wouldn't work (I have an in-cabin pet, and UA only allows them in the window seats in F on the 752).

What will be interesting is that I was already checked in, so I'm hoping the record didn't get completely hosed pet-wise. I'm now in a window seat again; I will check at NRT to make sure my pet record stayed intact.