Sprite reach beyond gameobjects bounds size and causing design problems

Im trying to set up design level through code with the help of SpriteRenderer. But my problem is that the Sprite reach beyond the current gameobjects bounds both x and y directions. The SpriteSheet is broken down in grid with all the same sizes (256*475) for all the parts with Unitys Sprite Editor.
Here is the code that replaces the sprites in x directions. Its working in all cases except this one. So the code should not be the problem here.

for (int lc = 0; lc < cl.childCount; lc++)
                            Transform imgTransformPart = cl.GetChild(lc);
                            sr = (SpriteRenderer)imgTransformPart.GetComponent(typeof(SpriteRenderer));
                            float sizeX = sr.bounds.size.x;
                            if (lc == 0)
                                orgPos = imgTransformPart.localPosition;
                                imgTransformPart.localPosition = new Vector3(orgPos.x, imgTransformPart.localPosition.y, imgTransformPart.localPosition.z);
                            else {
                                imgTransformPart.localPosition = new Vector3(orgPos.x + (sizeX * lc), imgTransformPart.localPosition.y, imgTransformPart.localPosition.z);

Im using Unity 5.1.3p2 but I dont think that should cause this bugg.

The result of this is sometimes you see a line in the background and overlapping of background design and I have no clue how I am gonna solve this.

Took a snapshoot to show what I mean.

I figured it out!
The more you compress the image the more the sprite reaches beoynd the gameobjects bounds.

No compresson = No problem.
Seems only be caused by spritesheets where sprite editors grid is used.

I havent test it in other versions of Unity but I will post it as a bug.