Several times (as late as this morning) I have checked Orbitz for Delta prices and found them to list Delta flights that Delta doesn't even list on their website. Example, going from TYS to MSY in September. Delta lists only the flights that connect through ATL while Orbitz lists the flights that connect through CVG....for the days and times I wanted, the CVG connection was cheaper and better flight times. Checked a second time with Delta online to verify that the flights were not listed, and then called Delta, and gave the agent the flights numbers for the CVG connection. She quoted me the same price as Orbitz and will be able to use my bump vouchers through Delta. This is not the first time I have run across the same situation. Moral of the story, its good to use several of the online resources before booking.
Spoilt