Problem with transparent materials and Directional light

Hi, I have a problem with directional light and transparent material.
Even if the directional light does not reach the transparent surface it changes its behavior.

This is how it looks with Directional light off (The cube in the middle is standard Transparent / diffuse shader and the others use a custom Transperent/reflective shader)

32372-light_off.jpg

And this is with it on
32373-light_on.jpg

As you can see the light result in artifacts in the surfaces. What could be wrong?

update:
One way of solving it was to move the objects that use transparent shader to a seperate layer and remove that layer from the culling mask. I do not know if this is the best option?

I’m not seeing any “artifacts” on your surfaces. I’m seeing the surfaces being lit by the directional light, exactly what should happen.

EDIT: I believe you might not understand exactly how directional lights work.

From Unity’s Manual:

Directional lights are placed infinitely far away and affect everything in the scene, like the sun.