Request the moderator relocate this thread to Travel Tools.

I have a second newbie question:
Why is my favorite tool (Yapta) for simple domestic commuter fares home providing incorrect pricing? When I get a Yapta alert of a fare drop and then check with the airline (US/B6), the Yapta fare cannot be confirmed with the airline/carrier. The yapta fares are sometimes off by more more then $100 for those same flight numbers.