Template instantiation conflict with function definition

Hello there!
While developing a policy-based application, I tried a code like this
one (which is real code).

I'm using g++ 4.3.3, which gives me these errors:
templ_error.cpp: In function =91int main()':
templ_error.cpp:22: error: multiple parameters named =91base'
templ_error.cpp:23: error: request for member =91exec' in =91test', whi=
ch
is of non-class type =91Test<Numeric<3>, Numeric<5> > ()(Numeric<3>,
Numeric<5>)'

But I can't understand where is the problem: it seems that g++ read my
declaration of a variable as a function definition. Please tell me if
I'm doing it wrong: I can't see the error.
Here's the code of templ_error.cpp

#include <iostream>

using namespace std;

template <typename A, typename B>
struct Test {
    A a;
    B b;
    Test(A a_, B b_): a(a_), b(b_) {}
    void exec() { cout << "Executed!" << a() << "-" << b() <<"\n"; }
};

template <int X>
struct Numeric {
    int base;
    Numeric(int base_): base(base_) {}
    int operator()() { return base + X; }
};

int main() {
    int base = 1;
    Test<Numeric<3>, Numeric<5> > test(Numeric<3>(base), Numeric<5>
(base));
    test.exec();
    return 0;
}

ps. Also with g++ 4.1 gives errors: the only difference is that
"multiple parameters name" is not present as it has introduced in gcc
4.3.

Any help is appreciated
Thanks!

Regards