Boost test memory leaks if virtual destructor implemented in source file

I am trying to run simple unit tests on a class, I get memory leaks detected whenever I implement a virtual destructor in the cpp file, rather than in the declaration.

This works and gives out no errors on the test below:

// Header file
class myClass
{
    myClass();
    virtual ~myClass(){};
};

This doesn't, it gives me memory leak detection:

/////// Header file
class myClass
{
    myClass();
    virtual ~myClass();
};


/////// CPP file
#include "myClass.h"

myClass::myClass(){}
myClass::~myClass(){}

Here's my test's code:

#include "myClass.h"
#define BOOST_TEST_MODULE myClassTestModule
#include "boost/test/unit_test.hpp"


BOOST_AUTO_TEST_CASE( u_wot_m8 )
{
    BOOST_CHECK(true);
}

The memory leak error shows:

Running 1 test case... 
*** No errors detected 
Detected memory leaks! 
Dumping objects -> 
{161} normal block at 0x00657BD8, 4 bytes long. 
 Data: < mp > E8 6D 70 10
Object dump complete.
Press any key to continue . . .

Why can this be?

Related questions:

A destructor function is causing a memory leak...