DKII on 02 August 2007
I don't own both but I can already tell you it's going to be a different code for each.
Did you know that your DS has a unique friend code too? And it's this code in combination with your game's serial number that generates each unique game's friend code? It's so you can only play each game online with a single DS. Kinda like registration keys on PC's. Insane anti-piracy fact for the day!
They can say each Mii has their own friend code but it might still just get used for generating user-specific and game-specific friend codes for each game to allow you to have multiple friends lists for the same game/system combination.
