The Air Dubrovnik flight is operating to Split in Croatia.
Chartered by Concorde Travel a Republic based tour operator. Seems however that the flight operates June - September from Knock, however tomorrow is their only BFS departure to Split. They also have a one off departure to Dubrovnik on the 20th June, using the season long Jet2 service. (Depending on website accuracy).
Croatia Tours who chartered the flights to Dubrovnik summer 2008 via Shannon, have a few sporadic dates over the summer to Dubrovnik using the Jet2 direct service also, and then on 4th October using Air Dubrovnik. (Again dependant on website accuracy).