connection point event is not fire from com component

Hi,

I have a com component and fire event to an MFC application using
connection point. But the wizard generated helper function in the event
procxy class does not fire event since the the m_vec is empty. I
suspect the ATLadvise has some problem, but the return result is OK.
can anyone tell me the possible cause? I have the following code.

//in component

//appwizard generated code. m_vec is empty

template <class T>
class CProxyIExtractEvent : public IConnectionPointImpl<T,
&IID_IExtractEvent, CComDynamicUnkArray>
{
    //Warning this class may be recreated by the wizard.
public:
    HRESULT Fire_OnExtractImage()
    {
        HRESULT ret;
        T* pT = static_cast<T*>(this);
        int nConnectionIndex;
        int nConnections = m_vec.GetSize();

        for (nConnectionIndex = 0; nConnectionIndex < nConnections;
nConnectionIndex++)
        {
            pT->Lock();
            CComPtr<IUnknown> sp = m_vec.GetAt(nConnectionIndex);
            pT->Unlock();
            IExtractEvent* pIExtractEvent =
reinterpret_cast<IExtractEvent*>(sp.p);
            if (pIExtractEvent != NULL)
                ret = pIExtractEvent->OnExtractImage();
        } return ret;

    }
};

.......

HRESULT CScribbleExtractor::Extract(HBITMAP* phBmpThumbnail)
{
    AFX_MANAGE_STATE(AfxGetStaticModuleState());

    Fire_OnExtractImage( );
}

//client code
class CTstConnect :
   public IDispatchImpl<IExtractEvent, &IID_IExtractEvent,
&CLSID_ScribbleExtractor>,
    public CComObjectRoot
{
public:
    CTstConnect() {}

   BEGIN_COM_MAP(CTstConnect)
       COM_INTERFACE_ENTRY(IDispatch)
       COM_INTERFACE_ENTRY(IExtractEvent)
   END_COM_MAP()

      //This method will be called when DoTest() is called, if this
object
      // has connected to the COM DLL (AtlAdvise)
 // HRESULT STDMETHODCALLTYPE OnExtractImage(LONG *pHBmpThumbnail )
      HRESULT STDMETHODCALLTYPE OnExtractImage()
   {
      AfxMessageBox("Hello");
      return S_OK;
   }
};

.......

BOOL CScribbleDoc::OnSaveDocument(LPCTSTR lpszPathName)
{
    // TODO: Add your specialized code here and/or call the base class
    HRESULT hRes = CoInitialize( NULL );
    ATLASSERT( SUCCEEDED(hRes) );

       //Initialize global CComModule
   _Module.Init( NULL, AfxGetInstanceHandle() );

    //Pointer to the interface defined in the COM DLL
    IScribbleExtractor *pM;

    //Create an instance of the interface defined in the COM DLL
    HRESULT theResult = CoCreateInstance( CLSID_ScribbleExtractor,
            NULL,
            CLSCTX_INPROC_SERVER,
            IID_IScribbleExtractor,
            (void**)&pM
            );

    if ( theResult != S_OK ) {
        std::ostringstream os;
        _com_error err(theResult);
        os << "CoCreateInstance() failed: " << err.ErrorMessage();
    }

    ATLASSERT(pM != NULL);

   //Create the COM object (client) that is to connect to the COM DLL
(server)
   CComObject<CTstConnect> *pTstConnect;

   //Create an instance of the client object
   CComObject<CTstConnect>::CreateInstance(&pTstConnect);

      //Variable for the connection point cookie
    DWORD dwAdvise = 0;

      //AtlAdvise, connect connection point
   hRes = AtlAdvise( pM,
                      pTstConnect->GetUnknown(),
                      IID_IExtractEvent,
                      &dwAdvise
                    );
   _ASSERT (SUCCEEDED (hRes));

    BOOL result = CDocument::OnSaveDocument(lpszPathName);

    AtlUnadvise(pM, IID_IExtractEvent, dwAdvise);

       //Finished with the server
   pM->Release();

      //Uninitialize to match CoInitialize
    CoUninitialize();

    return result;
}

//.idl file
import "oaidl.idl";
import "ocidl.idl";

    [
        object,
        uuid(9F236845-3E27-44f5-A939-682BABA892C2),
        dual,
        helpstring("IIconExtractor Interface"),
        pointer_default(unique)
    ]
    interface IScribbleExtractor : IDispatch
    {
    };

    [
    uuid(673B02F2-97D8-4b1f-9482-088C017E418E),
    version(1.0),
    helpstring("ConnectDemo 1.0 Type Library")
]
    interface IExtractEvent : IDispatch
    {
        [helpstring("method OnExtractImage")] HRESULT OnExtractImage();
    };

[
    uuid(7B077FC1-07BF-4184-89FB-9C09AD331380),
    version(1.0),
    helpstring("ThumbScb 1.0 Type Library")
]
library THUMBSCBLib
{
    importlib("stdole32.tlb");
    importlib("stdole2.tlb");

    [
        uuid(B3A3E4E4-08BE-4ad2-9333-E8958FA1E00D),
        helpstring("IconExtractor Class")
    ]
    coclass ScribbleExtractor
    {
        [default] interface IScribbleExtractor;
        [default, source] interface IExtractEvent;
    };
};