The entire listing of rules, which is somewhat lengthy, can be found at:
http://www.orbitz.com/pagedef/conten...Disabled=false
Apparently the mere fact that an airline lowers its price doesn't, in itself, trigger a refund from Orbitz. A lower priced ticket, presumably for the same itinerary, class of service, dates, etc, must be purchased, by someone else, ALSO through Orbitz. If I read the rules right Orbitz caps refunds at $250.