There are only 5 official Chinese iQue DS games. There are a TON of pirated/translated to Chinese games.
As I recall, the iQue DS has another processor? and if I remember correctly this handles an extra Chinese character table and it prevents iQue DS games from running properly on a NDS/L/i as far as I know.
If you try to run one on your DS(i) flashcard you only get a "Only on iQue DS" warning.