Problems with move constructor

I was testing a move constructor and did the following:

#include <iostream>
#include <string>
using namespace std;

class X{
    public:
        int* p;
        int size;
        X(){}
        X(int n) : size(n){
            p = new int[n];
            for(int i = 0; i < n; i++)
                p[i] = i;
            cout << "Constructor\n";
        }
        ~X(){
            delete[] p;
        }
        X(const X& r){
            cout << "Copy\n";

        }
        X(X&& r){
            p = r.p;
            size = r.size;
            r.p = NULL;
            r.size = 0;
            cout << "Move\n";
        }
};
int main() {
    X a(10); //constructor    
    X b(a); // copy
    X c(X(3)); //constructor, move
    return 0;
}

What I expected in the output is in the comments, but when compiling (VS 2012) move constructor is not called?! But, if I add additional parameter to constructor:

string name;
X(int n, string _name) : size(n), name(_name){
    p = new int[n];
    for(int i = 0; i < n; i++)
        p[i] = i;
    cout << "Constructor\n";
}

and then

X a(10, "a"); //constructor
X b(a); // copy
X c(X(3, "pom")); //constructor, move

i get results as expected... I really don't understand why.

EDIT: Now tested on GCC 4.7.2 and it does not call Move constructor in both cases but C++ Builder XE5 compiler calls Move constructor in both cases. Yet, VS calls it only in the second case (when using additional constructor parameter). Very interesting...