Masking shader with alpha Color

Hi !

I’m working on a basic masking shader (texture image + texture mask) that allow one to have any images masked by a texture where all white part are shown and all transparent part are transparent. This works really great but does not support alpha.
Indeed I would like to add fadeIn and FadeOut operation to my object with the masking shader. Thus I end up with this :

Shader "Custom/Masking" {
	Properties
    {
      _Color ("Main Color", Color) = (1, 1, 1, 1)
      _MainTex ("Base (RGBA)", 2D) = "white" {}
      _Mask ("Culling Mask", 2D) = "white" {}
      _Cutoff ("Alpha cutoff", Range (0,1)) = 0.1
 	}
 	
	SubShader {
		Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}
		LOD 200
		
		Lighting Off
	    ZWrite Off
	    Blend SrcAlpha OneMinusSrcAlpha
	    AlphaTest GEqual [_Cutoff]
	    
	    
        Pass {
	      SetTexture [_Mask] {combine texture}
	      SetTexture [_MainTex] {
	      	combine texture, previous * constant ConstantColor[_Color]
	      }
	      
	    }
	} 
}

It is borrowed from the wiki + constantColor is aded to handle alpha ! I works, but, all the texture under this one does not show up.
For instance, I have a glow quad behind my masking shader plan. This glow plan appear fine until I add the alpha to the shader plan.

Any help would be appreciate.

Thanks !

P.S : here is the second glow shader :

Shader "Glow" {
Properties {
	_TintColor ("Tint Color", Color) = (0.5,0.5,0.5,0.5)
	_MainTex ("Particle Texture", 2D) = "white" {}
	_InvFade ("Soft Particles Factor", Range(0.01,3.0)) = 1.0
    _GlowTex ("Glow", 2D) = "" {}
    _GlowColor ("Glow Color", Color)  = (1,1,1,1)
    _GlowStrength ("Glow Strength", Float) = 1.0
}

Category {
	Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderEffect"="Glow11Transparent" "RenderType"="Glow11Transparent"  }
	Blend SrcAlpha OneMinusSrcAlpha
	AlphaTest Greater .01
	ColorMask RGB
	Cull Off Lighting Off ZWrite Off
	BindChannels {
		Bind "Color", color
		Bind "Vertex", vertex
		Bind "TexCoord", texcoord
	}
	
	// ---- Fragment program cards
	SubShader {
		Pass {
		
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#pragma fragmentoption ARB_precision_hint_fastest
			#pragma multi_compile_particles
			
			#include "UnityCG.cginc"

			sampler2D _MainTex;
			fixed4 _TintColor;
			
			struct appdata_t {
				float4 vertex : POSITION;
				fixed4 color : COLOR;
				float2 texcoord : TEXCOORD0;
			};

			struct v2f {
				float4 vertex : POSITION;
				fixed4 color : COLOR;
				float2 texcoord : TEXCOORD0;
				#ifdef SOFTPARTICLES_ON
				float4 projPos : TEXCOORD1;
				#endif
			};
			
			float4 _MainTex_ST;

			v2f vert (appdata_t v)
			{
				v2f o;
				o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
				#ifdef SOFTPARTICLES_ON
				o.projPos = ComputeScreenPos (o.vertex);
				COMPUTE_EYEDEPTH(o.projPos.z);
				#endif
				o.color = v.color;
				o.texcoord = TRANSFORM_TEX(v.texcoord,_MainTex);
				return o;
			}

			sampler2D _CameraDepthTexture;
			float _InvFade;
			
			fixed4 frag (v2f i) : COLOR
			{
				#ifdef SOFTPARTICLES_ON
				float sceneZ = LinearEyeDepth (UNITY_SAMPLE_DEPTH(tex2Dproj(_CameraDepthTexture, UNITY_PROJ_COORD(i.projPos))));
				float partZ = i.projPos.z;
				float fade = saturate (_InvFade * (sceneZ-partZ));
				i.color.a *= fade;
				#endif
				
				return 2.0f * i.color * _TintColor * tex2D(_MainTex, i.texcoord);
			}
			ENDCG 
		}
	} 	
	
	// ---- Dual texture cards
	SubShader {
		Pass {
			SetTexture [_MainTex] {
				constantColor [_TintColor]
				combine constant * primary
			}
			SetTexture [_MainTex] {
				combine texture * previous DOUBLE
			}
		}
	}
	
	// ---- Single texture cards (does not do color tint)
	SubShader {
		Pass {
			SetTexture [_MainTex] {
				combine texture * primary
			}
		}
	}
}
CustomEditor "GlowMatInspector"
}

I think this can be helpful