Inhertiance question

Hi Experts,

I have been having some strange things happening in my code.  It worked one or two times and not after.  I began to doubt there is some problem in the way I am using inheritance/polimorphism.  here is the simplified version of the code.  Am I doing something wrong?  I tried this in visual studio 6.0 and it seems to work all the time.( Printing 3)

#include <iostream>

using namespace std;

class A
{
      
public:
      A() {};
      ~A() {};
      virtual int getMember(){ return 0;};
      virtual void setMember(int i ) { memA = 0;};
private:
      int memA;
      
};

class B : public A
{
public:
      B(){ };
      ~B(){ };
      int getMember(){return memB;};
      void setMember(int a){ memB = a; };
private:
      int  memB;
};

class X
{
public:
      X(){};
      ~X(){};
      void setSomething(A& a){ cout << a.getMember() << endl;};
      
};



int main()
{

      X *xx = new X();
      B *ab = new B();
      ab->setMember(3);

      xx->setSomething(*ab);

      return 0;
}