Audio problem: In the scene where Matthew Broderick is addressing the potential members of the 54th on horseback (right after he accepts the position), the army band is playing, but the visuals don't match the music. While we hear drumrolls, we only see single hits on the snare drums by the actors. And at least one drummer is playing in mid-air.
Audio problem: Much of Karen's drumming is not in sync with the drum sounds.