FX/TrigField question

Hello,

I've been using the FX/TrigField shader by Thomas Phillips for my latest project. On my MacBookPro it looks really nice. But I just recently created a Build and tested my game on an iMac i5 2.7GHz. The same shader which looks awesome in my computer, looks terribly wrong on the iMac. It creates a noise instead of the actual shader. I am wondering, why is this happening? Could this have something to do with the Graphics card? I'm attaching the code of the shader, could someone could have a look at it? Thanks!
Nick.

Code (csharp):

1. // Upgrade NOTE: replaced 'PositionFog()' with multiply of UNITY_MATRIX_MVP by position
2. // Upgrade NOTE: replaced 'V2F_POS_FOG' with 'float4 pos : SV_POSITION'
3.  
4. //
5. // Shader: "FX/TrigField"
6. // Version: v1.0
7. // Written by: Thomas Phillips
8. //
9. // Anyone is free to use this shader for non-commercial or commercial projects.
10. //
11. // Description:
12. // Generic force field effect.
13. // Play with color, opacity, and rate for different effects.
14. //
15.  
16. Shader "FX/TrigField" {
17.  
18. Properties {
19.     _Color ("Color Tint", Color) = (0, 0, 0.5, 1.0)
20.     _Rate ("Oscillation Rate", Range (1, 10)) = 1.0
21.     _Scale ("Ripple Scale", Range (1, 30)) = 10.0
22. }
23.  
24. SubShader {
25.    
26.     ZWrite Off
27.     Tags { "Queue" = "Transparent" }
28.     Blend One One
29.  
30.     Pass {
31.  
32. CGPROGRAM
33. // Upgrade NOTE: excluded shader from Xbox360 because it uses wrong array syntax (type[size] name)
34. #pragma exclude_renderers xbox360
35.  
36. // Define/undefine either/both of these for a differnt variant.
37. #define USE_TAN
38. #undef USE_LINES
39.  
40. #pragma vertex vert
41. #pragma fragment frag
42. #pragma fragmentoption ARB_fog_exp2
43. #include "UnityCG.cginc"
44.  
45. float4 _Color;
46. float _Rate;
47. float _Scale;
48.  
49. struct v2f {
50.     float4 pos : SV_POSITION;
51.     float4 texcoord : TEXCOORD0;
52.     float4[4] target : TEXCOORD1;
53. };
54.  
55. v2f vert (appdata_base v)
56. {
57.     v2f o;
58.     o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
59.     o.texcoord = v.texcoord;
60.     int j;
61.     for ( j = 2; j < 5; j++) {
62.         float a, b;
63.         sincos(j*_Time[0], a, b);
64.         o.target[j-2] = float4(a, b, 0, 0);
65.     }
66.     return o;
67. }
68.  
69. half4 frag (v2f i) : COLOR
70. {
71.     float4 d;
72.     int j;
73.     float r = _Time[1] * _Rate;
74.     for ( j = 0; j < 3; j++) {
75. #ifdef USE_LINES
76. #ifdef USE_TAN
77.         d[j] = tan(_Scale * dot(i.texcoord, i.target[j]) - r);
78. #else
79.         d[j] = sin(_Scale * dot(i.texcoord, i.target[j]) - r) * 3;
80. #endif
81. #else
82. #ifdef USE_TAN
83.         d[j] = tan(_Scale * distance(i.texcoord, i.target[j]) - r);
84. #else
85.         d[j] = sin(_Scale * distance(i.texcoord, i.target[j]) - r) * 3;
86. #endif
87. #endif
88.     } // for
89.     return half4( (dot(d, d) * _Color).xyz, 1 );
90. }
91. ENDCG
92.  
93.     }
94. }
95. Fallback "Transparent/Diffuse"
96. }

 

i copied but i got a message error