Where to free memory?

Hello all,
Let's say I have two classes A and B defined as follows:

// ClassA.h //////////////////////////
class ClassA
{
public:
  void ClassA(int nItems); // constructor
  virtual ~ClassA();
protected:
  double *myTable; // My table of nItems double values
}
/////////////////////////////////////

// ClassA.cpp ///////////////////////
void ClassA(int nItems)
{
  // Allocate memory for the table of double values
  myTable=(double*)calloc(nItems, sizeof(double));
}

~ClassA()
{
// Should I free the memory allocated for myTable here?
// free(myTable);
// myTable=NULL;
}
/////////////////////////////////////

// ClassB.h //////////////////////////
#include "ClassA.h"
class ClassB
{
public:
  void ClassB();
protected:
  ClassA classA(int nItems);
}
/////////////////////////////////////

// ClassB.cpp ///////////////////////
void ClassB()
{
classA=new ClassA(10);
}
/////////////////////////////////////

My question is: when should I free the memory allocated for myTable
array of object classA ?
I am using MS Visual C++ 6.0 and Vista. Given the above code, I get a
memory leak. OK.
But if I free the memory as commented out in the destructor, I get an
error message pointing at the free(myTable) line
"memory check error at 0x02FDAA50 = 0xFE, should be 0xFD."
What is the correct way to free the memory ?
TIA,
Phil