It work fine with me.
Strange the description you found ; with the multiple Microsoft's exercises , i always the same déclaration :

VertexShader =
decl
{
stream 0;
float v0[3]; // Position
float v3[3]; // Normal
float v7[3]; // Texture coord1
float v8[3]; // Texture coord2
}
or

VertexShader =
decl
{
stream 0;
float v0[3]; // Position
float v3[3]; // Normal
float v7[3]; // Texture Coord1
float v8[3]; // Tangent
}