The system also gets really cranky when you try to look up a hub-to-hub flight, like JFK-BOS or JFK-IAD. It gives you the same error message that all flights must originate or end in either LGB, BOS, NYC or IAD--even though in this instance the flight both originates and ends in one of these cities.

Interestingly, last time I checked the system can handle JFK-LGB flights.