C2070 - illegal sizeof operand

The following code looks fine to me:

    #include <stdio.h>

    template <typename T>
    struct A
    {
        static float m_kA[];
    };

    template <typename T>
    float A<T>::m_kA[] = {1.0f, 2.0f, 3.0f};

    int main()
    {
        printf("%d\n", 
            sizeof(A<unsigned int>::m_kA) /
            sizeof(A<unsigned int>::m_kA[0]));
        return 0;
    }

But when i compile with VC9 i get the following error

error C2070: 'float []': illegal sizeof operand

I would expect this code to compile. Am i missing something? Does anyone know a way to fix this strange behavior (note that the exact same thing without the template compiles fine and outputs 3).

Note that removing the template is not an option, i made this example to reproduce a problem that i'm having in a code where i need the type containing the array to be a template.

Thanks