Yapta may be unable to price a flight for a variety of reasons, including:

1.    The flight number may have changed
2.    The flight schedule may have changed
3.    The flight may have been cancelled

Yapta will let you know when your flights can not be priced with a message that says "review flight info."  Users can edit the flight information with updated flight information by clicking the "review flight info" link. 

Users can also search for similar flights.  Click "Search Similar" in the "Flight Actions" dropdown box on the Flight Details page.  This will trigger a search for flights that match the same detination/dates.  New flights can be tracked directly from the search results.