Hyrule Warriors

I've been playing it constantly since I got it and have not encountered a single freeze or any frame rate problems. Notably though since Americans got the game I've been hearing them complaining of freezing and framerate issues. I'm wondering if there is something wrong with the US copies?

The problems are becoming more apparent due to a larger audience having access to the game now. From what I've read, the freezing is a rather rare occurrence, but Chapters 4 and 15 apparently have an above average chance to kill the game.

I've had no issues with the game otherwise.