Insufficient Resources

Can't work out how to solve the following error. I get that the TEXCOORD problem is coming around from exceeding the maximum of 8 texcoords. However, without the following lines (see below) the Input struct works fine, so I'm guessing the compiled code is creating an extra texcoord or resource in the code below. If I uncomment these lines the shader has enough resources to compile and display. Any ideas how to fix this?

The shader I'm using is a modified version of the BumpSpecProbe shader by Zomby138 (which can be found here). Basically the same shader with an added decal texture.

Any help would be great

Cheers. Alex.

P.S. Using shader model 3, Unity 4.2

Errors:

Program 'frag_surf', input semantic attribute "TEXCOORD" has too big of a numeric index ( 8 ) at line 193
Program 'vert_surf', cannot locate suitable resource to bind parameter "_ShadowCoord" at line 193


Code Snippet:

This is the code breaking the shader, everything else works fine.

Code (csharp):

1.                 o.Normal = normalize(o.Normal);
2.                 fixed3 worldN = WorldNormalVector(IN, o.Normal);
3.                 fixed3 worldR = normalize(WorldReflectionVector(IN, o.Normal));
4.                 float3 fProbeSpecCol = ShadeSH9(float4(worldR,1.0));
5.                 float fProbeSpecMask = pow(max(_ProbeSpecStr*(length(fProbeSpecCol)-_ProbeSpecSub Fresnel0*2),0),_ProbeShininess+Fresnel0);
6.                 o.Emission = o.Albedo*ShadeSH9(float4(worldN,1.0)) + o.Gloss*fProbeSpecCol*fProbeSpecMask;

 

If anyone can please help it'd be really appreciated. We're now unfortunately looking at removing light probes due to not being able to solve this issue.

It's related to the question I asked yesterday morning http://answers.unity3d.com/questions/504703/bumpedspecprobed-decal-uv2.html