i understand the problem (i can read german )
but i suck at writing german, so i'll post in English (could do dutch if you prefer ).

you need to set a background color for your level in order to make it stop doing that strange background copying.

in main, before the level load type:

Code:

---

 
sky_color.red = 0;
sky_color.green = 0;
sky_color.blue = 255; // bright blue sky   
 

---

have fun with it ^_^

regards,