The production was staged before--in 2003.
The disputed scene is not part of Mozart's opera but was added as a sort of coda by the director, Hans Neuenfels. In it, the king of Crete, Idomeneo, carries the heads of Muhammad, Jesus, Buddha and Poseidon onto the stage, placing each on a stool.
The scene aroused controversy among Muslims and Christians when the Deutsche Oper first staged the production. But the opera was not the target of any organized protests, and the Deutsche Oper scheduled four performances for November.
The Berlin police said they received a call this summer from an unidentified person, who warned that the opera was "damaging to religious feelings." The caller did not make a specific threat against the opera.
ADDED: An opera by Mozart that'll really offend Muslims.