Problem with shadows overlapping the object when the normal is reversed

Hi, I have been trying to find a cut-out shader that supports casting and receiving shadows. I found a couple of shaders that fullfilled the requirements, (like this one: http://wiki.unity3d.com/index.php/Transparent_Diffuse_Two_Pass_Lit_Shadows) but almost all them showed problems sorting the image itself and its shadow. This particular shader draws the shadow first when the object is flipped (when the normal is reversed). Here is a screenshot of what is looks like:



Does anyone know how this could be fixed? Or perhaps someone can think of a different way of doing this?

By the way I am using Unity Pro, version 3.5.7.

 

In case anyone ever find themselves with the same problem, what I ended up doing was following the advice from this article: http://danielbrauer.com/files/rendering-double-sided-geometry.html, and making the objects double-sided. Cheers!