Audio problem: Every time a sword is drawn, be it fast or slow, there is the 'shiiink' sound that is made when a steel sword is drawn from a steel scabbard (a sound that a western sword would make), yet Japanese swords have a wooden scabbard so the draw should be silent.
Audio problem: In the scene where Algren is talking to Katsumoto about General Custer, there is a shot from behind Katsumoto's head and it is clear that he is talking and yet his mouth isn't moving.
Audio problem: When Algren fights the five "ronin," he does not shout out when he kicks at one of his opponents; yet in a flashback a few moments later, it is obvious that a war cry was added in.
Answer: The Battle of Thermopylae, see http://en.wikipedia.org/wiki/Battle_of_Thermopylae for more info.
Myridon