I have been trying to book a multi-city itinerary I found on ITA at united.com. It lets me select my flights, and then when I hit "continue" or whatever, it throws an error and tells me to call United to book.

Is this common, or is something just screwed up today? I ended up booking at Expedia, but would have preferred to book directly. I didn't call because of the surcharge.

Thanks-
Eric