In the Extended 0.41, how do I apply a shader?

Hmm, I'm sure that works great, although I guess my shader is dodgy because the sprite seems to be showing a solid colour, although the colour does change from blacks and browns as I move around the map.

Do you see anything wrong with my shader?

bloom.frag

uniform sampler2D bgl_RenderedTexture;

void main()
{
   vec4 sum = vec4(0);
   vec2 texcoord = vec2(gl_TexCoord[0]);
   Int j;
   Int i;

   For( i= -4 ;i < 4; i++)
   {
        For (j = -3; j < 3; j++)
        {
            sum += texture2D(bgl_RenderedTexture, texcoord + vec2(j, i)*0.004) * 0.25;
        }
   }
       If (texture2D(bgl_RenderedTexture, texcoord).r < 0.3)
    {
       gl_FragColor = sum*sum*0.012 + texture2D(bgl_RenderedTexture, texcoord);
    }
    Else
    {
        If (texture2D(bgl_RenderedTexture, texcoord).r < 0.5)
        {
            gl_FragColor = sum*sum*0.009 + texture2D(bgl_RenderedTexture, texcoord);
        }
        Else
        {
            gl_FragColor = sum*sum*0.0075 + texture2D(bgl_RenderedTexture, texcoord);
        }
    }
}