Pixel bender edges problem

Question

i'm trying to make simple light shader, here is my code:
<languageVersion : 1.0;>
kernel SimpleLight
<   namespace : "Your Namespace";
    vendor : "Yossi";
    version : 1;
>
    input image4 src;
    output pixel4 dst;
    parameter float3 lightPosition
        <
           defaultValue: float3(0,0,-100);
        >;
    void
    evaluatePixel()
        pixel4 pixel = sampleNearest(src,outCoord());
        float3 Normal = float3(0.0,0.0,-1.0);
        float3 pixelPos = float3(0.0,0.0,0.0);
        float3 Kd = float3(pixel.r,pixel.g,pixel.b);
        float3 lightDir = lightPosition - pixelPos;
        float diffuse = dot(Normal,normalize(lightDir)); 
        float3 res = Kd * (diffuse + specular);
        dst = pixel4(res.x,res.y,res.z,pixel.a);
now here is the source image:
http://tinypic.com/view.php?pic=2w3nw2q&s=5
and here is the resault:
http://tinypic.com/r/245bxtv/5
instead of getting clean pic i get this thin white line on the right.
when i run it on "GPU" or "CPU" it's ok, but on "FLASH" i get this.
can anyone explane how to solve it?
thank you.

Answer 1

i'm very sorry here is the code (working) :
<languageVersion : 1.0;>
kernel SimpleLight
<   namespace : "Your Namespace";
    vendor : "Yossi";
    version : 1;
>
    input image4 src;
    output pixel4 dst;
    parameter float3 lightPosition
        <
           defaultValue: float3(0,0,-100);
        >;
    void
    evaluatePixel()
        pixel4 pixel = sampleNearest(src,outCoord());
        float3 Normal = float3(0.0,0.0,-1.0);
        float3 pixelPos = float3(0.0,0.0,0.0);
        float3 Kd = float3(pixel.r,pixel.g,pixel.b);
        float3 lightDir = lightPosition - pixelPos;
        float diffuse = dot(Normal,normalize(lightDir));
        float3 res = Kd * (diffuse);
        dst = pixel4(res.x,res.y,res.z,pixel.a);