problem with CDataSource Open

Hello!

I have a MFC Dll where I have a call to Open for a CDataSource object.
I get error when calling Open for object of CDataSource
the error code from this call is -2147024770 which is 0x8007007e
To make it easy for me do debug I created a MFC application by using MFC
Appwizard(exe).

The code in CTestApp::InitInstance() is generated except for the code that
follows
the text MyCode.(see below)

I can use odbc to connect to the database by using testconnection which
returns with successful.
Here is the data thta I use.
DataSourceName: IDTHU1
TNS Service Name: IDTHU1
ServiceName: IDTHU1
UserName: CCR_DTH_USER
Password: P55534552

When I use the degugger and step into the open for object CDataSource
I get error in the open method where a call is made to method
CoCreateInstance.
This method returns -2147024770 which is 0x8007007E.

The code that follows the text MyCode below is just a copy from the real Dll
and is old code
that is not written by me.

I can't understand why it doesn't work. I'm very uncertain about this
statement
const GUID ORAPROPSET_COMMANDS = \
    {0x8B92E3F1,0x4C70,0x11D4,{0x91,0x1B,0x00,0xC0,0x4F,0x4C,0x7E,0x26}};
this is used in statement CDBPropSet dbPropset(ORAPROPSET_COMMANDS);

BOOL CTestApp::InitInstance()
{
 AfxEnableControlContainer();

 // Standard initialization
 // If you are not using these features and wish to reduce the size
 // of your final executable, you should remove from the following
 // the specific initialization routines you do not need.

#ifdef _AFXDLL
 Enable3dControls(); // Call this when using MFC in a shared DLL
#else
 Enable3dControlsStatic(); // Call this when linking to MFC statically
#endif

 // Change the registry key under which our settings are stored.
 // TODO: You should modify this string to be something appropriate
 // such as the name of your company or organization.
 SetRegistryKey(_T("Local AppWizard-Generated Applications"));

 LoadStdProfileSettings(); // Load standard INI file options (including
MRU)

 // Register the application's document templates. Document templates
 // serve as the connection between documents, frame windows and views.

 CSingleDocTemplate* pDocTemplate;
 pDocTemplate = new CSingleDocTemplate(
  IDR_MAINFRAME,
  RUNTIME_CLASS(CTestDoc),
  RUNTIME_CLASS(CMainFrame), // main SDI frame window
  RUNTIME_CLASS(CTestView));
 AddDocTemplate(pDocTemplate);

 // Parse command line for standard shell commands, DDE, file open
 CCommandLineInfo cmdInfo;
 ParseCommandLine(cmdInfo);

 // Dispatch commands specified on the command line
 if (!ProcessShellCommand(cmdInfo))
  return FALSE;

 // The one and only window has been initialized, so show and update it.
 m_pMainWnd->ShowWindow(SW_SHOW);
 m_pMainWnd->UpdateWindow();

 /************************************************************/
 /* MyCode
*/
 /************************************************************/

  LPCTSTR UserId = "CCR_DTH_USER";
 LPCTSTR Password = "P55534552";
 LPCTSTR DataSource = "IDTHU1";
 CString strTemp = "OraOLEDB.Oracle";

 const GUID ORAPROPSET_COMMANDS = \
    {0x8B92E3F1,0x4C70,0x11D4,{0x91,0x1B,0x00,0xC0,0x4F,0x4C,0x7E,0x26}};

    HRESULT hr S_OK;

 CDataSource DS;
 CDBPropSet dbInit(DBPROPSET_DBINIT);
  CDBPropSet dbPropset(ORAPROPSET_COMMANDS);

 dbInit.AddProperty(DBPROP_AUTH_USERID, UserId);
 dbInit.AddProperty(DBPROP_AUTH_PASSWORD, Password);
 dbInit.AddProperty(DBPROP_INIT_DATASOURCE, DataSource);
 dbInit.AddProperty(DBPROP_INIT_LCID, (long)1053);
 dbInit.AddProperty(DBPROP_INIT_PROMPT, (short)4);
 dbInit.AddProperty(DBPROP_INIT_PROVIDERSTRING, OLESTR(""));

 hr = DS.Open(strTemp, &dbInit);

 return TRUE;
}

Does anybody have any suggestion how to solve my problem.

//Tony