Has anyone had success getting PR_DEFAULT_STORE using MAPI under Windows Mobile?

Question

The following piece of test code runs under Windows Mobile. It's objective is to seek out the default message store. This is so that I can get the proper account name for programmatically compiling an email.

IMAPISession *mapiSession;
HRESULT hr = S_OK;

MAPIInitialize (NULL);
IMAPITable *msgTable;

SRowSet *pRows;
IMsgStore *msgStore;

if (MAPILogonEx(0,NULL,NULL,0,&mapiSession) != S_OK)
{
//  MessageBox(g_hWnd,_T("Failed to logon"),_T("Error"),0);
}
else
{
SizedSPropTagArray(3, PropTagArr) = {3,{PR_DISPLAY_NAME, 
      PR_ENTRYID,
      PR_DEFAULT_STORE}};

    hr = mapiSession->GetMsgStoresTable(MAPI_UNICODE,&msgTable);

    hr = msgTable->SetColumns((LPSPropTagArray)&PropTagArr, 0);

    if (!hr)
    {
     do
     {
      hr = msgTable->QueryRows(1,0,&pRows);

      LPSPropValue lpProp;
      lpProp = &pRows->aRow[0].lpProps[0];

//    if(_tcscmp( lpProp->Value.LPSZ, _T("SMS") ) == 0 )
//     break;

      lpProp = &pRows->aRow[0].lpProps[0];
      if (lpProp->ulPropTag == PR_DEFAULT_STORE)
       break;

      lpProp = &pRows->aRow[0].lpProps[1];
      if (lpProp->ulPropTag == PR_DEFAULT_STORE)
       break;

      lpProp = &pRows->aRow[0].lpProps[2];
      if (lpProp->ulPropTag == PR_DEFAULT_STORE)
       break;

      FreeProws(pRows);
      pRows = NULL;

     }while (!hr);

 hr = mapiSession->OpenMsgStore (0, 
   pRows->aRow[0].lpProps[1].Value.bin.cb, 
   (ENTRYID*)pRows->aRow[0].lpProps[1].Value.bin.lpb, 
   NULL, 
   MDB_NO_DIALOG | MAPI_BEST_ACCESS, 
   &msgStore);

... BUT, fails to get the PR_DEFAULT_STORE property on a Windows Mobile device. I'm guessing Microsoft didn't implement it accurately. And so, lpProp->ulPropTag will never == PR_DEFAULT_STORE. It's always 0000.

Which leads me to my question, is there another way of the determing the default message store?

Thank you.