I have tried cube-map normalization like this:

Texture cubemap_normalize< string ResourceName = "normalize.dds";
string TextureType = "CUBE"; >;
samplerCUBE normalize_sampler = sampler_state {texture = <cubemap_normalize>;
AddressU = CLAMP;
AddressV = CLAMP;
AddressW = CLAMP;
MIPFILTER = LINEAR;
MINFILTER = LINEAR;
MAGFILTER = LINEAR;
};
inline float3 my_normalize(float3 V)
{
return (float3) texCUBE( normalize_sampler, V ) * 2.0 - 1.0;
}

then I got error say "dependent texture read chain cannot exceed 1 in ps_1_4" at texCUBE(..) line. Is the mistake in the cube-map?
and what is normalize.dds looks like?