i need urgent help regarding the collision detection problem i had in my game, before i exported the game into my iphone, everything is working file, including the collision detection and stuff, i even tried building it out in other platforms like PC, mac and all is working too, only unity iphone doesnt work. can anyone please tell me whats wrong?

below is my code for the collision part.

//Collision Detection between player and carrots. function OnCollisionEnter( collision : Collision ) {

    if(collision.gameObject.tag == "Carrot1" && playerNo == 1 && carrotNo == 1)
    {
        Destroy(collision.gameObject); //Destroy Current Gameobject that is being touched.
        scores.addScore();
        scores.addMultiply();
    }
    else if(collision.gameObject.tag == "Carrot1" && playerNo == 2 && carrotNo == 2)
    {
        Destroy(collision.gameObject);
        scores.addScore();
        scores.addMultiply();
    }

    if(collision.gameObject.tag == "Carrot2" && playerNo == 1 && carrotNo2 == 1)
    {
        Destroy(collision.gameObject);
        scores.addScore();
        scores.addMultiply();
    }
    else if(collision.gameObject.tag == "Carrot2" && playerNo == 2 && carrotNo2 == 2)
    {
        Destroy(collision.gameObject);
        scores.addScore();
        scores.addMultiply();
    }
}

am i doing anything wrong? in the game itself it just doesnt seem to detect the collision.

PLEASE, any suggestion is welcome. )';