Shader Outline scale problem since U5

Hello all,

Since Unity 5 I have a problem in with my 'outline diffuse' shader.

So, the problem: it seems like the outline is unproportionally scaled to the size of an object. See example bellow: these are twice the exact same object with the same shader/material. But the small one is scaled on xyz to .2 of its original size.

Would any of you know how to correct this?

PS: Let me admit that I try my best learning everything I can to develop a game, but shader code is still chineese to me... :(

Here is the shader code used:

 //credits: http://wiki.unity3d.com/index.php/Outlined_Diffuse_3
 //credits bis: http://answers.unity3d.com/questions/742645/shader-outlined-diffuse-with-vertex-color.html
 
 Shader "Outlined/Diffuse" {
     Properties {
         _Color ("Main Color", Color) = (.5,.5,.5,1)
         _OutlineColor ("Outline Color", Color) = (0,0,0,1)
         _Outline ("Outline width", Range (.002, 0.03)) = .005
         _MainTex ("Base (RGB)", 2D) = "white" { }
     }
 
     CGINCLUDE
     #include "UnityCG.cginc"
 
     struct appdata {
         float4 vertex : POSITION;
         float3 normal : NORMAL;
     };
 
     struct v2f {
         float4 pos : POSITION;
         float4 color : COLOR;
     };
 
     uniform float _Outline;
     uniform float4 _OutlineColor;
 
     v2f vert(appdata v) {
         // just make a copy of incoming vertex data but scaled according to normal direction
         v2f o;
         o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
 
         float3 norm   = mul ((float3x3)UNITY_MATRIX_IT_MV, v.normal);
         float2 offset = TransformViewToProjection(norm.xy);
 
         o.pos.xy += offset * o.pos.z * _Outline;
         o.color = _OutlineColor;
         return o;
     }
     ENDCG
 
     SubShader {
         //Tags {"Queue" = "Geometry+100" }
         CGPROGRAM
         #pragma surface surf Lambert
 
         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;
         }
         ENDCG
 
         // note that a vertex shader is specified here but its using the one above
         Pass {
             Name "OUTLINE"
             Tags { "LightMode" = "Always" }
             Cull Front
             ZWrite On
             ColorMask RGB
             Blend SrcAlpha OneMinusSrcAlpha
             //Offset 50,50
 
             CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             half4 frag(v2f i) :COLOR { return i.color; }
             ENDCG
         }
     }
 
     SubShader {
         CGPROGRAM
         #pragma surface surf Lambert
 
         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;
         }
         ENDCG
 
         Pass {
             Name "OUTLINE"
             Tags { "LightMode" = "Always" }
             Cull Front
             ZWrite On
             ColorMask RGB
             Blend SrcAlpha OneMinusSrcAlpha
 
             CGPROGRAM
             #pragma vertex vert
             #pragma exclude_renderers gles xbox360 ps3
             ENDCG
             SetTexture [_MainTex] { combine primary }
         }
     }
 
     Fallback "Diffuse"
 }

Thank you for your help & happy coding!