Using get_documentElement cause exception in Application exit

[Yoavo]

Hi,
I am trying to read an XML file using get_documentElement method and I get
exception when the application exits in comip.h file (in _Release() method).
I am just Loading the XML file and use get_documentElement method:

bool CProfileTranslationToolDlg::TranslateFile(const _bstr_t& TrnURI)
{
// Load XML file.
MSXML2::IXMLDOMDocument2Ptr pDoc;
HRESULT hr = pDoc.CreateInstance(__uuidof(MSXML2::XML_DOMDOCUME NT));
if (FAILED(hr))
return false;
VARIANT_BOOL vb = pDoc->load(TrnURI);
if (!vb)
return false;
hr = pDoc->get_documentElement(&mDocElem);
return true;
}

when "mDocElem" is a member of CProfileTranslationToolDlg class, and
declared in this way:
private:
MSXML2::IXMLDOMElementPtr mDocElem;

I noticed that if I declare mDocElem as MSXML2::IXMLDOMElement* I do not get
the exception.

Can someone please explain ?
Yoav.