Am I doing something wrong, or is the UA seat mapper function not very smart? Here's the scenario:

going UA 875 DEN to NRT. It's a 757 from DEN to SEA, and a 777 from SEA to NRT. However if I try to access the seat map function, all it shows is the 757 and will not allow me to see seats on the 777 from SEA to NRT. The only way that I've figured out around this is use the multiple city function and tell it I want to go DEN-SEA-NRT, then it works.

Any pointers would be greatly appreciated.