delete doesn't appear to delete

[mop65715]

The singleton class based off the CRTP is not provided, nonetheless consider.

# include <iostream>
# include <map>
# include <string>
# include <vector>

class Base { 
public: 
  virtual ~Base() {} 
};

class  Derived : public Base { 
public: 
  Derived()  {}
  ~Derived() { std::cout << "o" << std::endl; } 
};

enum TEST_KEYS { A, B, C, END_OF_KEYS };

class test :  public singleton < test > {
  typedef TEST_KEYS test_keys;
  Base *key_list[ END_OF_KEYS ];
public :
 template < typename ClassType >
 test& insert ( test_keys const & key, ClassType * ptr ) {
   if ( key_list [ key ] != 0 ) {
     throw ( std::runtime_error( "key exists" ) );
   } 
   key_list [ key ] = ptr;
   return ( *this );
  }

 template < typename ClassType >
 Derived& Get ( test_keys const & key ) {
   if ( key_list [ key ] == 0 ) {
     throw ( std::runtime_error( "no match" ) );
   }
   //I think static_cast here should suffice
   return static_cast< ClassType& >( *( key_list [ key ] ) );
  }

   template < typename ClassType >
   void Delete ( test_keys const & key ) {
     if ( key_list [ key ] != 0 ) {
       delete key_list[ key ];
     }
   }
};

//later 
int main() {

  for ( int odx ( 0 ) ; odx < 2; ++odx ) {
    test::instance().insert < Derived >(  A, new Derived () );
    //now remove it...
    test::instance().Delete < Derived > ( A ) ;
  }
  std::cin.get();
}

It appears that the derived class 'Derived' is not being 'Deleted' from the m_list even though it's clear from debugging and stream output that the destructor of the Derived class is called. That said, on the next call to insert (i.e when odx = 1) the exception 'key exists' is thrown. (I'll admit that after a handful of years with C++ I'm embarassed to admit I'm struggle with what appears to be the basics)

How do I resolve this?