They have an episode in the 3rd or 4th season where kent brockman does a news story on cheap korean animation. They show a room with like 100 malnourished looking people sitting elbow to elbow at drafting tables drawing and korean soldiers with bayonets prodding them. On the dvd commentary matt groening was saying that korea almost refused to animate it. I guess they weren't too happy.
There's always jokes about the korean animation though. Wasn't there an episode this season where homer makes fun of the quality and then they purposely show his mouth separate from his head and continue to talk.
