Audio problem: When Annie says, "Did you drive up from San Francisco by the coast road?" her lips are mouthing something different. (00:17:55)
Audio problem: At one point, I think it's when they arrive at the dead Hydra, Aeetes' Captain (with the brown "bobble-hat" and the moustache) says a line like "Some of you up there....and that way," and is pointing to direct the soldiers. It is very obvious that he is not saying this line and that it was dubbed on afterwards.
Audio problem: While Marcello Mastroianni is waiting at the station and Sandra Milo's train can be heard arriving off-screen, we hear much whistling by a steam train, but when it finally appears, the train is being hauled by a diesel locomotive. [As a side note/explanation - all sound in Italian movies, including the dialogue, is recorded afterwards, sometimes by different actors, eg. Claudia Cardinale in real life has a regional accent.]