Cocos2d - Iphone scheduleUpdate update not being called

I have a Player class that extends CCNode, and i want to hava a method that is called开发者_Python百科 every frame (update). In my init method i added the following line of code [self scheduleUpdate]; but my -(void) update:(ccTime)deltaTime method is never called why is that?

is the player added to the main node ?? with the addchild function ? I mean if you have another class which uses a player instance, you should add the player to that class with the addchild method