Objects passing through collision because of transform.translate

Hi,

I have an object that falls using rigidbody.AddForce not the default gravity.

And when you press left/right you move the object in order to navigate around obstacles.

My problem is that the player object will often pass through the wall objects i have even used waitForSecconds to temporary disable the controls but the problem still persists.

 static var power : float = 0.0;
 static var myY : float;
 
 public var upperClampLimit : float; // can be changed form editor
 public var lowerClampLimit : float; // can be changed from editor
 public var fallAcceleration : float; // can be changed from editor
 public var wallSlow : float; //can be changed from editor
 public var movementShrinkerhoriz : float; // can be changed form editor
 public var movementShrinkervert : float; // can be changed form editor
 
 var shouldMove : boolean = true;
  
 function Start(){
  
 rigidbody.freezeRotation = true;
     
 }
     
 function Update (){
 Debug.Log (shouldMove);  
     
 var horiz : float = Input.GetAxis("Horizontal");
 var horizMovement = horiz/movementShrinkerhoriz;
 
 if (shouldMove) {
 transform.Translate(Vector3(horizMovement,0,0));
 }
      
 if (horizMovement!=0){
 rigidbody.velocity.x = 0;
 
 }
      
 var vert : float = Input.GetAxis("Vertical");
 var vertMovement = vert/movementShrinkervert;
 power = power - vertMovement;   
 power = power +fallAcceleration;

 if (power <=0){  
 power = power +fallAcceleration;
 }
 rigidbody.AddForce(Vector3(0,-power,0));
        
 var dist = (transform.position - Camera.main.transform.position).z;
 var upBorder = Camera.main.ViewportToWorldPoint(Vector3(0,upperClampLimit,dist)).y;
 var downBorder = Camera.main.ViewportToWorldPoint(Vector3(0,lowerClampLimit,dist)).y;   
 transform.position.y = Mathf.Clamp(transform.position.y,upBorder,downBorder);
   
 }
     
 function FixedUpdate (){
     
 myY = (rigidbody.position.y);
 rigidbody.transform.position.z = 0;
     
 }
      
 function OnCollisionEnter(theCollision : Collision){  
 if(theCollision.gameObject.name == "wall"){
 shouldMove = false;
 yield WaitForSeconds(0.5);
 shouldMove = true;
 
     
 if (power <=0){
  
 power = power -wallSlow;
 }
       
 }
 }