beginner: assertion error on class export from dll

Hi everybody...

im stuck and after crawling thru usenet for days and still beeing
unable to solve my problem, i post it.

what i want is: i want a dll export a class.
what i've read and tried to understand is...

http://www.codeproject.com/dll/dlltips.asp?df=100&forumid=855&exp=0&select=615608
what i did is listed below.
what i got is...

-------------------------------------------------
| Debug Assertion Failed! |
| |
| Program: (path to my prog) |
| File: dbgheap.c |
| Line: 1011 |
| |
| Expression: _CrtIsValidHeapPointer(pUserData) |
-------------------------------------------------

what i'd really apreciate is some enlightenment what im doing wrong.

currently im doing it wrong with microsoft vc++ 6; here's the code:

##########################################
# THE APPLICATION #
##########################################

__________________________________________
// ---------------------------------
// apl.h
// ---------------------------------

HINSTANCE hDLL;

__________________________________________
// ---------------------------------
// apl.cpp
// ---------------------------------

#include "apl.h"
#include "test.h"

// [...]

    hDLL = LoadLibrary("test");
    typedef CFoo* (*MYFUNC)(DWORD);

    if (hDLL != NULL) {
            MYFUNC pnMyfunc = (MYFUNC) GetProcAddress(hDLL, "CreateFoo");
        CFoo* pFoo = pnMyfunc(0);
        pFoo->Initialize(_T("check"));
            delete pFoo;
        FreeLibrary(hDLL);
    }

// [...]

##########################################
# THE DLL #
##########################################
__________________________________________
// ---------------------------------
// test.def
// ---------------------------------

LIBRARY "test"
DESCRIPTION 'Test for Windows DLL'

EXPORTS
CreateFoo @1

__________________________________________
// ---------------------------------
// StdAfx.h
// ---------------------------------

#if !defined(AFX_STDAFX_H_9234592646__INCLUDED_)
#define AFX_STDAFX_H_9234592646__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#define WIN32_LEAN_AND_MEAN

#include <windows.h>

#endif // AFX_STDAFX_H_9234592646__INCLUDED_

__________________________________________
// ---------------------------------
// test.h
// ---------------------------------

#include <string>

class CFoo {
public:
    virtual void Initialize (std::string sName) = 0;
};

__________________________________________
// ---------------------------------
// test.cpp
// ---------------------------------

#include "StdAfx.h"
#include "test.h"

BOOL APIENTRY DllMain( HANDLE hModule, DWORD ul_reason_for_call, LPVOID
lpReserved) {
    switch (ul_reason_for_call) {
        case DLL_PROCESS_ATTACH:
        case DLL_THREAD_ATTACH:
            break;
        case DLL_THREAD_DETACH:
        case DLL_PROCESS_DETACH:
            break;
    }
    return TRUE;
}

class CFooImp : public CFoo {
public:
    CFooImp();
    virtual ~CFooImp();

    void Initialize (std::string sName) {
        m_sName = sName;
    }

protected:
    std::string m_sName;
};

CFooImp::CFooImp() {}

CFooImp::~CFooImp() {}

__declspec(dllexport) CFoo* CreateFoo(DWORD dwVersion) {
    if (dwVersion == 0) return new CFooImp;
    return NULL;
}