Rotating Wrong

when the AI moves towards me it rotates forward for some reason, same as when it sees my player if I move it'll tilt the model forward a little and then when he chases me it doesn't work very well it just stays where it rotated to and ends up flipping everywhere, Ive added a ridgidbody.. but it still hasn't worked. Is they a way I can make it not rotate? I've froze the rotation using the ridgidbody.

My code is below.

 var Distance;
 var Target : Transform;
 var lookAtDistance = 25.0;
 var attackRange  = 15.0;
 var moveSpeed = 5.0;
 var Daping = 6.0;
 var myTrans : Transform;
 
 
 private var anim : Animator;
 
 function Start () {
         anim = GetComponent(Animator);
 }
 
 function Update () 
 {
             Distance = Vector3.Distance(Target.position, transform.position);
             if (Distance < lookAtDistance) 
             {
                 anim.SetBool("Walking", false);
                 Debug.Log("Looking at Player!");
                 lookat ();
                 
             }
             
             if (Distance > lookAtDistance)
             {    
                 Debug.Log("Looking For Player!");
                 
             }
             
             if (Distance < attackRange)
             
             {
                 transform.Translate(Vector3.forward * moveSpeed * Time.deltaTime);
                 //anim.SetBool("Walking", true);
                 Debug.Log("Attacking");
             }
             
             
 }
 
 function lookat () {
     var rotation = Quaternion.LookRotation(Target.position - transform.position);
     transform.rotation = Quaternion.Slerp(transform.rotation, rotation, Time.deltaTime * Daping);
 }
 
 function attackPlayer () {
     //transform.Translate(Vector3.forward * moveSpeed * Time.deltaTime);
 }