Why this Distortion Shader Different in Unity3.4.

The Shader: // Upgrade NOTE: replaced 'glstate.matrix.modelview[0]' with 'UNITY_MATRIX_MV' // Upgrade NOTE: replaced 'glstate.matrix.mvp' with 'UNITY_MATRIX_MVP'

 Shader "HeatDistortion" {
 Properties {
     _NoiseTex ("Noise Texture (RG)", 2D) = "white" {}
     strength("strength", Range(0.1, 0.3)) = 0.2
     transparency("transparency", Range(0.01, 0.1)) = 0.05
 }
 
 Category {
     Tags { "Queue" = "Transparent+10" }
     SubShader {
         GrabPass {
             Name "BASE"
             Tags { "LightMode" = "Always" }
         }
        
         Pass {
             Name "BASE"
             Tags { "LightMode" = "Always" }
             Lighting Off
             Cull Off
             ZWrite On
             ZTest LEqual
             Blend SrcAlpha OneMinusSrcAlpha
             AlphaTest Greater 0
          
          
 CGPROGRAM
 // Upgrade NOTE: excluded shader from Xbox360; has structs without semantics (struct v2f members distortion)
 #pragma exclude_renderers xbox360
 #pragma vertex vert
 #pragma fragment frag
 #pragma fragmentoption ARB_precision_hint_fastest
 #pragma fragmentoption ARB_fog_exp2
 #include "UnityCG.cginc"
 
 sampler2D _GrabTexture : register(s0);
 float4 _NoiseTex_ST;
 sampler2D _NoiseTex;
 float strength;
 float transparency;
 
 struct data {
     float4 vertex : POSITION;
     float3 normal : NORMAL;
     float4 texcoord : TEXCOORD0;
 };
 
 struct v2f {
     float4 position : POSITION;
     float4 screenPos : TEXCOORD0;
     float2 uvmain : TEXCOORD2;
     float distortion;
 };
 
 v2f vert(data i){
     v2f o;
     o.position = mul(UNITY_MATRIX_MVP, i.vertex);      // compute transformed vertex position
     o.uvmain = TRANSFORM_TEX(i.texcoord, _NoiseTex);   // compute the texcoords of the noise
     //float viewAngle = dot(normalize(mul((float3x3)glstate.matrix.invtrans.modelview[0], i.normal)),
     //                     float3(0,0,1));
     float viewAngle = dot(normalize(ObjSpaceViewDir(i.vertex)),
                          i.normal);
     o.distortion = viewAngle * viewAngle;    // square viewAngle to make the effect fall off stronger
     float depth = -mul( UNITY_MATRIX_MV, i.vertex ).z;    // compute vertex depth
     o.distortion /= 1+depth;        // scale effect with vertex depth
     o.distortion *= strength;    // multiply with user controlled strength
     o.screenPos = o.position;   // pass the position to the pixel shader
     return o;
 }
 
 half4 frag( v2f i ) : COLOR
 {   
     // compute the texture coordinates
     float2 screenPos = i.screenPos.xy / i.screenPos.w;   // screenpos ranges from -1 to 1
     screenPos.x = (screenPos.x + 1) * 0.5;   // I need 0 to 1
     screenPos.y = (screenPos.y + 1) * 0.5;   // I need 0 to 1
 
     // check if anti aliasing is used
     if(_ProjectionParams.x < 0)
         screenPos.y = 1 - screenPos.y;
    
     // get two offset values by looking up the noise texture shifted in different directions
     half4 offsetColor1 = tex2D(_NoiseTex, i.uvmain + _Time.xz);
     half4 offsetColor2 = tex2D(_NoiseTex, i.uvmain - _Time.yx);
    
     // use the r values from the noise texture lookups and combine them for x offset
     // use the g values from the noise texture lookups and combine them for y offset
     // use minus one to shift the texture back to the center
     // scale with distortion amount
     screenPos.x += ((offsetColor1.r + offsetColor2.r) - 1) * i.distortion;
     screenPos.y += ((offsetColor1.g + offsetColor2.g) - 1) * i.distortion;
     
     half4 col = tex2D( _GrabTexture, screenPos );
     col.a = i.distortion/transparency;
     return col;
 }
  
 ENDCG
         }
     }
 }
 
 }

I USE plane in front of Camera. But Everything Looks Revers!!!! this Origin Shader Is Not AutoUpdate in Unity2.6. so it works...How to fix it in unity3d 3.4..

125*Origin Shader:*125

 Shader "HeatDistortion" {
 
 Properties {
 
     _NoiseTex ("Noise Texture (RG)", 2D) = "white" {}
 
     strength("strength", Range(0.1, 0.3)) = 0.2
 
     transparency("transparency", Range(0.01, 0.1)) = 0.05
 
 }
 
  
 
 Category {
 
     Tags { "Queue" = "Transparent+10" }
 
     SubShader {
 
         GrabPass {
 
             Name "BASE"
 
             Tags { "LightMode" = "Always" }
 
         }
 
        
 
         Pass {
 
             Name "BASE"
 
             Tags { "LightMode" = "Always" }
 
             Lighting Off
 
             Cull Off
 
             ZWrite On
 
             ZTest LEqual
 
             Blend SrcAlpha OneMinusSrcAlpha
 
             AlphaTest Greater 0
 
          
 
          
 
 CGPROGRAM
 
 #pragma vertex vert
 
 #pragma fragment frag
 
 #pragma fragmentoption ARB_precision_hint_fastest
 
 #pragma fragmentoption ARB_fog_exp2
 
 #include "UnityCG.cginc"
 
  
 
 sampler2D _GrabTexture : register(s0);
 
 float4 _NoiseTex_ST;
 
 sampler2D _NoiseTex;
 
 float strength;
 
 float transparency;
 
  
 
 struct data {
 
     float4 vertex : POSITION;
 
     float3 normal : NORMAL;
 
     float4 texcoord : TEXCOORD0;
 
 };
 
  
 
 struct v2f {
 
     float4 position : POSITION;
 
     float4 screenPos : TEXCOORD0;
 
     float2 uvmain : TEXCOORD2;
 
     float distortion;
 
 };
 
  
 
 v2f vert(data i){
 
     v2f o;
 
     o.position = mul(glstate.matrix.mvp, i.vertex);      // compute transformed vertex position
 
     o.uvmain = TRANSFORM_TEX(i.texcoord, _NoiseTex);   // compute the texcoords of the noise
 
     float viewAngle = dot(normalize(ObjSpaceViewDir(i.vertex)),
 
                          i.normal);
 
     o.distortion = viewAngle * viewAngle;   // square viewAngle to make the effect fall off stronger
 
     float depth = -mul( glstate.matrix.modelview[0], i.vertex ).z;  // compute vertex depth
 
     o.distortion /= 1+depth;        // scale effect with vertex depth
 
     o.distortion *= strength;   // multiply with user controlled strength
 
     o.screenPos = o.position;   // pass the position to the pixel shader
 
     return o;
 
 }
 
  
 
 half4 frag( v2f i ) : COLOR
 
 {   
 
     // compute the texture coordinates
 
     float2 screenPos = i.screenPos.xy / i.screenPos.w;   // screenpos ranges from -1 to 1
 
     screenPos.x = (screenPos.x + 1) * 0.5;   // I need 0 to 1
 
     screenPos.y = (screenPos.y + 1) * 0.5;   // I need 0 to 1
 
  
 
     // check if anti aliasing is used
 
     if (_ProjectionParams.x < 0)
 
         screenPos.y = 1 - screenPos.y;
 
    
 
     // get two offset values by looking up the noise texture shifted in different directions
 
     half4 offsetColor1 = tex2D(_NoiseTex, i.uvmain + _Time.xz);
 
     half4 offsetColor2 = tex2D(_NoiseTex, i.uvmain - _Time.yx);
 
    
 
     // use the r values from the noise texture lookups and combine them for x offset
 
     // use the g values from the noise texture lookups and combine them for y offset
 
     // use minus one to shift the texture back to the center
 
     // scale with distortion amount
 
     screenPos.x += ((offsetColor1.r + offsetColor2.r) - 1) * i.distortion;
 
     screenPos.y += ((offsetColor1.g + offsetColor2.g) - 1) * i.distortion;
 
    
 
     half4 col = tex2D( _GrabTexture, screenPos );
 
     col.a = i.distortion/transparency;
 
     return col;
 
 }
 
  
 
 ENDCG
 
         }
 
     }
 
 }
 
  
 
 }

Please...Help me...i am not good at Shader...