Strange behavior in a network rigidbody

Hi there, in my multiplayer game I'm having this problem which I couldn't find a solution yet:

There's a only ball in the server, the ball has a rigidbody.

Once the player gets the ball, the ball becomes the child of a child of player object. Then the player is able to kick the ball.

Here goes the RPC script of the kick ("bola" means "ball"):

 var bola = transform.FindChild("+esferaPlayer").FindChild("+bola(Clone)");
 bola.rigidbody.isKinematic = false;
 bola.transform.parent = null;
 bola.rigidbody.AddForce(transform.forward * 10, ForceMode.Impulse);
   

And it works fine, but only for the server!

When a client tries kicking the ball, either the ball quickly goes then comes back to the player or the ball isn't even kicked.

So the player needs to keep pressing the button 'till the ball finally gets kicked.

There's a message in the log: "Receiving state for an object whose network view exists but the observed object no longer exists"

I don't think it has anything to do with the bug, but you never know...

You can test it here: www.golonline.net/play.html

Thanks.