Yea, I was surprised too. This is the first instance I have run into where ITA has more difficulty getting it to come up than united.com. Actually, as I type this, I can't get ITA to bring it up. I can do the one-ways through Asiana and ANA, so I know they work, but making them work together is another story).

Tried some other spots: Expedia can find the flights, but fails when it trys to price it. Travelocity and Orbitz were both struggling.. Hmm.