Thanks.
Unfortunatelly the code is written in C++ and it is difficult to post the
entire project here. But here is the PresentationSave (dispid 2005) event
handler :

STDMETHODIMP CPPTSink::OnPresentationSave(IDispatch *pPresentation)
{
   OutputDebugString("OnPresentationSave\n");

   CComQIPtr<_Presentation> ptrPresentation(pPresentation);
   if(!ptrPresentation)
       return E_POINTER;

   // Get the FullName property value
   CComBSTR bstrFullName = ptrPresentation->FullName.copy(); // here I get
the right value

   _Application *pApplication = NULL;
   try
   {
       // get the _Application interface pointer from GIT
       HRESULT hr = m_pGIT->GetInterfaceFromGlobal(m_dwApplication,
__uuidof(_Application), (void**)&pApplication);
       if(FAILED(hr) || NULL == pApplication)
           return hr;

       // Open temporary, invisible, presentation
       CComPtr<_Presentation> ptrTempPresentation =
pApplication->Presentations->Open(_bstr_t(_T("c:\\test.ppt")), msoFalse,
msoFalse, msoTrue);
       if(ptrTempPresentation)
       {
           // Get the FullName property value
           bstrFullName = ptrPresentation->FullName.copy(); // here I still
get the right value

           // Close temporary presentation
           ptrTempPresentation->Close();
       }

       // Get the FullName property value
       bstrFullName = ptrPresentation->FullName.copy();  // here I get a
wrong value like "Presentation1"

       // Release _Application interface
       pApplication->Release();
       pApplication = NULL;
   }
   catch(_com_error &e)
   {
       OutputDebugString(e.ErrorMessage());
       HRESULT hr = e.Error();
   }
   catch(...)
   {
       OutputDebugString("C++ exception in CPPTSink::ConnectSink");
   }
}

best regards, Calin