Audio problem: In the scene in the beginning when the dance is going on, it shows John playing the trumpet. When he starts on his solo, there is s shot where it zooms in on the bell of the trumpet. During this shot you hear a single note being played and not changing. But if you look, you can see John moving his fingers on the valves.
Audio problem: When Vercingétorix tells Caesar that Alexander the Great was dead by the time he was Caesar's age, his mouth movements don't match the words. In this shot he is, I think, speaking French with the English dubbed over - he looks like he is saying 'mort'. (00:24:50)