hr = ::CoLockObjectExternal(m_pIDropTarget, TRUE, FALSE);
if ( FAILED(hr) ) {
wxLogApiError(wxT("CoLockObjectExternal"), hr);
hr = ::CoLockObjectExternal(m_pIDropTarget, TRUE, FALSE);
if ( FAILED(hr) ) {
wxLogApiError(wxT("CoLockObjectExternal"), hr);