(NGUI) display a charactor with a surface shader , on Android platform some mobile phone will shake the screen

there is a part of the surface shader,please help me find issue in this shader that create this question !!

Shader "ActionX/Actor" { Properties { //主纹理 _MainTex ("Base (RGB)", 2D) = "white" {} //主颜色（用于发色） _MainColor ("Main Color", Color) = (1,1,1,1) //纹理颜色置灰 [MaterialToggle] _ToGray ("ToGray", Float) = 0 //开启纹理叠加 [MaterialToggle] _OpenTO ("OpenTO", Float) = 0 //叠加的纹理 _TextureOverlay ("Texture Overlay", 2D) = "black" {} //开启颜色叠加（用于虚化） [MaterialToggle] _OpenCO ("OpenCO", Float) = 0 //叠加的颜色（用于虚化） _ColorOverlay ("Color Overlay", Color) = (1,1,1,1) //叠加的百分比值（用于虚化） _OverlayValue ("Overlay Value", Range(0,1)) = 0 //开启发光 [MaterialToggle] _OpenRI ("OpenRI", Float) = 0 //外发光颜色 _RimColor ("Rim Color", Color) = (0.5,0.5,0.5,0.5) //内发光颜色 _InnerColor ("Inner Color", Color) = (0.5,0.5,0.5,0.5) //发光强度 _Power ("Power(0-10)", Range(0,2)) = 2 //环境光颜色 _AmbientColor ("Ambient Color", Color) = (0.509,0.509,0.509,1) [HideInInspector]_Cutoff ("Alpha cutoff", Range(0,1)) = 0.5 } SubShader { Tags { "RenderType"="Opaque" "LightMode"="Always" } LOD 200

 CGPROGRAM
 #pragma surface surf Lambert

 sampler2D _MainTex;
 fixed4 _MainColor;

 half _ToGray;

 half _OpenTO;
 uniform sampler2D _TextureOverlay;uniform fixed4 _TextureOverlay_ST;

 half _OpenCO;
 fixed4 _ColorOverlay;
 half _OverlayValue;

 half _OpenRI;
 fixed4 _RimColor;
 fixed4 _InnerColor;
 half _Power;

 fixed4 _AmbientColor;

 struct Input {
     half3 viewDir;
     half2 uv_MainTex;
 };

 void surf (Input IN, inout SurfaceOutput o) {
     fixed4 c = tex2D(_MainTex, IN.uv_MainTex);
     if (_ToGray > 0.6)
     {
         c.rgb = c.r * 0.299 + c.g * 0.587 + c.b * 0.114;
     }
     o.Albedo = c.rgb * _MainColor * (1 - c.a) + c.rgb * c.a;
     if (_OpenTO > 0.6)
     {
         fixed4 t = tex2D(_TextureOverlay, TRANSFORM_TEX(IN.uv_MainTex, _TextureOverlay));
         o.Albedo = saturate(max(c.rgb, t.rgb));
     }
     o.Albedo = o.Albedo * _AmbientColor * 2;
     if (_OpenCO > 0.6)
     {
         o.Albedo = o.Albedo + (_ColorOverlay * _OverlayValue);
     }
     else
     {
         if (_OpenRI > 0.6)
         {
             half rim = 1.0 - saturate(dot (normalize(IN.viewDir), o.Normal));
             half power = pow (rim, _Power);
             o.Emission = (_RimColor.rgb + _InnerColor.rgb * 2) * power;
         }
     }
 }
 ENDCG
 }
 FallBack "Diffuse"

}