Camera: objects shown multiple times at once

Hey there,

I've got a weird problem with Unity. I am developing some kind of billard game in 2D. Therefore I have an orthographic camera. At the image you can see the borders (in grey) and three balls. But if you look on the left and right of the borders the balls and parts of the borders are drawn again - it looks so crazy and I don't have any idea where it could come from. There is only one camera in the scene and the script attached to it looks like this:

 using UnityEngine;
 using System.Collections;
 
 public class CameraAspect : MonoBehaviour {
 
     // Use this for initialization
     void Start () {        
         // set the desired aspect ratio (the values in this example are
         // hard-coded for 16:9, but you could make them into public
         // variables instead so you can set them at design time)
         float targetaspect = 10.0f / 16.0f;
         
         // determine the game window's current aspect ratio
         float windowaspect = (float)Screen.width / (float)Screen.height;
         
         // current viewport height should be scaled by this amount
         float scaleheight = windowaspect / targetaspect;
         
         // if scaled height is less than current height, add letterbox
         if (scaleheight < 1.0f)
         {
             Rect rect = camera.rect;
 
             rect.width = 1.0f;
             rect.height = scaleheight;
             rect.x = 0;
             rect.y = (1.0f - scaleheight) / 2.0f;
             
             camera.rect = rect;
         }
         else // add pillarbox
         {
             float scalewidth = 1.0f / scaleheight;
 
             Rect rect = camera.rect;
             
             rect.width = scalewidth;
             rect.height = 1.0f;
             rect.x = (1.0f - scalewidth) / 2.0f;
             rect.y = 0;
             
             camera.rect = rect;
         }
         
     }
 
     
 }
 

Does anybody have an idea how to solve that or what could the problem beneath? Thanks a lot in advance!

PS: in the editor game-view the scene just looks fine. The problem described above occurs on my Nexus4 and HTC Desire HD.