Camera movement performs different with different inputs

Hello! Im am creating game map which is seen from 90degrees above. (The game is on Android).The camera has a script which gets user input and pans(moves x,y) the camera on map. Problem is that when I test in Editor with mouse I get the expected performance - everything works great, lerp etc.. But when I test in Android device with touch, the performance is like jumping around and lerp is not working. What is the problem?

 private var yaxis:float;
 private var xAxis:float;
 private var vertSpeed:float;
 private var horiSpeed:float;
 public var rotationSpeed: float;
 public var lerpSpeed: float;
 public var krabis:GUIText;
 
 var cameraTopLimit: float;
 var cameraBottomLimit:float;
 
 var cameraTopLimit2: float;
 var cameraBottomLimit2:float;
  
   
 
 function Update () {

     if(Input.GetMouseButton(0) ) {
   
         yaxis = -Input.GetAxis("Mouse Y");
         vertSpeed = yaxis;
         xAxis = Input.GetAxis("Mouse X");
         horiSpeed = xAxis;
         
     } 
     else {
         var ix = Time.deltaTime * lerpSpeed;
         vertSpeed = Mathf.Lerp(vertSpeed, 0, ix);
         horiSpeed = Mathf.Lerp(horiSpeed, 0, ix);
     }

     
     var limitY = Mathf.Clamp(transform.position.x + (vertSpeed * rotationSpeed), cameraBottomLimit, cameraTopLimit);
     transform.position.x = limitY;
     
     var limitX = Mathf.Clamp(transform.position.z + (horiSpeed * rotationSpeed), cameraBottomLimit2, cameraTopLimit2);
     transform.position.z = limitX;
     

     krabis.text = ": " + yaxis;
 }

Thanks!