Problem with trasparency of window thickness

I have a problem with a transparent shader that i use for a window, some part of the mesh is not rendered as you can see in the picture.

The red lines show the part that should be visible in the render but that does not appear.
Here you can see the code of the shader:

Shader "Custom/myTransDif" {

	Properties {
		_Color ("Main Color", Color) = (1,1,1,1)
		_SpecColor ("Spec Color", Color) = (1,1,1,0)
	    _Emission ("Emissive Color", Color) = (0,0,0,0)
	    _Shininess ("Shininess", Range (0.1, 1)) = 0.7
		_MainTex ("Base (RGB) Trans (A)", 2D) = "white" {}

	SubShader {
		Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}
		// added
		//Lighting Off
       	//Cull Back
		ZWrite on
		Pass {ColorMask A}
		Blend SrcAlpha OneMinusSrcAlpha
    	Cull Off //Front
    	AlphaTest Off
		// end added
		LOD 200
		#pragma surface surf Lambert alpha
		sampler2D _MainTex;
		fixed4 _Color;
		struct Input {
			float2 uv_MainTex;
		void surf (Input IN, inout SurfaceOutput o) {
			fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
			o.Albedo = c.rgb;
			o.Alpha = c.a;

	Fallback "Transparent/VertexLit"

Does anyone know how to fix this?
Thanks in advance

You can see a demo here:

I think you need to have normal on the other window too ( i mean double-faced normal )
Sorry if i’m wrong, this is my only suggestion.

Thanks for the reply,
unfortunately unity does not work with double side materials,
the geometry that you see are two solids together, the problem is that the glass part seems to hides the geometry nearby and show only those far.
If I use the standard material “transparent / diffuse” the glass works correctly but all the window becomes semi-transparent and i don’t know why.
The alpha channel of the texture is all white except the glass that are 50% black.

Does anyone have any idea?