One, make sure that your aircraft have the appropriate characteristics set. Even if you listed the aircraft as a "Boeing 747", the software won't know that it's a complex aircraft unless you checked the 'complex' box.

Two, in some cases, you may have to save one more flight to trigger the recalculation. Just go into any flight in 'edit' mode and then without any changes, click on 'save.' This will trigger the recalculation and you'll be happy (alternately, you can add a new flight to trigger a save.. it's the same either way).