Shader rendering in 4.3, not 4.5

I’m using a relatively simple shader to mask out shapes over curvy HUD elements in a mobile game. This displays properly on the device when built in 4.3, and it displays correctly in the 4.5 editor, but not when run on iOS after building in 4.5. The camera renders everything as if there is no mask present.

Does anyone know a reason this may happen? The shader I’m using is as follows:

Shader "TextureMask"

{

   Properties

   {

      _Mask ("Culling Mask", 2D) = "white" {}

   }

   SubShader

   {

      Tags {"Queue" = "Background"}

      Blend SrcAlpha OneMinusSrcAlpha

      Lighting Off

      ZWrite On

      ZTest Always

      Alphatest LEqual 0

      Pass

      {

         SetTexture [_Mask] {combine texture}

      }

   }

}

Try add your shader into list of imported shaders. Project → Settings → Always Including Shader

Thanks for the suggestion mf_andreich, but that didn’t make a difference. It seems Unity is including this shader either way but simply does not render it.