why I can't connect remote com inside a com component?

hi,
    I write a com componenet with atl named "substation" and I can connected
this remote componenet use a mfc dialog client,but when I use the same code
to connect the same remote component inside the com return E_ACCESSDENIED?
why?

thanks a lot!

the source code:

idl:

// StarSvr.idl//

import "oaidl.idl";
import "ocidl.idl";

[
 object,
 uuid(CF53159E-4893-474B-B819-3A93BA30623E),
 helpstring("ISubstation interface"),
 pointer_default(unique)
]
interface ISubstation : IUnknown{
 [helpstring("method OnTime")] HRESULT OnTime([in] BSTR host, [in] VARIANT
varTime);
 [helpstring("method Add")] HRESULT Add([in] LONG l1, [in] LONG l2, [out]
LONG* lR);
 [helpstring("method ConnectTo")] HRESULT ConnectTo([in] BSTR host, [in]
BSTR user, [in] BSTR pass, [in] BSTR domain);
 [helpstring("method SetName")] HRESULT SetName([in] BSTR name);
};
[
 uuid(F3A94BC5-8EE8-478D-AAAD-8A9EBE406CFA),
 version(1.0),
 helpstring("StarSvr 1.0 library")
]
library StarSvrLib
{
 importlib("stdole2.tlb");
 [
  uuid(BE5F9E61-26D0-4F52-AD6F-EFD1262C5F1A),
  helpstring("Substation Class")
 ]
 coclass Substation
 {
  [default,source] interface ISubstation;
 };
};

mfc dialog connect code:
 COSERVERINFO si;
 ZeroMemory(&si, sizeof(si));
 COAUTHIDENTITY author_id;
 ZeroMemory(&author_id, sizeof(COAUTHIDENTITY));

 author_id.Flags =SEC_WINNT_AUTH_IDENTITY_UNICODE;//
SEC_WINNT_AUTH_IDENTITY_ANSI ;
 author_id.User = (unsigned short*)m_sUserName.GetBuffer();
 author_id.UserLength = _tcslen((TCHAR*)author_id.User);
 author_id.Domain = (unsigned short*)m_sDomain.GetBuffer();;
 author_id.DomainLength = _tcslen((TCHAR*)author_id.Domain);
 author_id.Password = (unsigned short*)m_sPassword.GetBuffer();
 author_id.PasswordLength = _tcslen((TCHAR*)author_id.Password);

 COAUTHINFO athn;
    ZeroMemory(&athn, sizeof(COAUTHINFO));
 athn.dwAuthnSvc =
RPC_C_AUTHN_WINNT;//RPC_C_AUTHN_GSS_KERBEROS;//RPC_C_AUTHN_WINNT;
    athn.dwAuthzSvc = RPC_C_AUTHZ_NONE;
 athn.dwAuthnLevel = RPC_C_AUTHN_LEVEL_CALL;//RPC_C_AUTHN_LEVEL_NONE;//
    athn.dwCapabilities = EOAC_NONE;
    athn.dwImpersonationLevel = RPC_C_IMP_LEVEL_IMPERSONATE;
    athn.pAuthIdentityData = &author_id;
    athn.pwszServerPrincName = NULL;

 si.pwszName = m_sHostName.GetBuffer();//
L"\\\\mywin2k3";//L"\\\\Chenxingtian-pc";
    si.pAuthInfo = &athn;
    si.dwReserved1 = 0;
    si.dwReserved2 = 0;

 MULTI_QI rgmqi[2];
 ZeroMemory(rgmqi, sizeof(rgmqi));
 rgmqi[0].pIID = &IID_ISubstation;
 rgmqi[1].pIID = &IID_IConnectionPointContainer;

 hRes = CoCreateInstanceEx(CLSID_Substation, NULL, CLSCTX_REMOTE_SERVER,
&si, 2, rgmqi);
 if (hRes == S_OK)
 {
  m_pSubstation = (ISubstation*)rgmqi[0].pItf;
  m_pConnectionPointContainer = (IConnectionPointContainer*)rgmqi[1].pItf;
 // pClientSecurity = (IClientSecurity*)rgmqi[2].pItf;
 }
 else
 {
  CString str;
  str.Format(_T("CoCreateInstanceEx Error! Error number
is:%x,%s"),hRes,_com_error(hRes).Description());
  m_ctrlEditMsg.ReplaceSel(str);
  return ;
 }
 ATLASSERT(m_pSubstation != NULL);
hRes = m_pConnectionPointContainer->FindConnectionPoint(IID_ISubstation,
&m_pConnectionPoint);
 ASSERT(SUCCEEDED(hRes));
hRes = m_pConnectionPoint->Advise((IUnknown*)m_pSubstationCon, &m_dwAdvise);
 if(hRes != S_OK)
 {
  CString str;
  str.Format(_T("Advise Error! Error number is:%x"),hRes);
  m_ctrlEditMsg.ReplaceSel(str);
  return ;
 }

 ATLENSURE(SUCCEEDED(hRes) && m_dwAdvise != 0);

//connect inside com:

STDMETHODIMP CSubstation::ConnectTo(BSTR host, BSTR user, BSTR pass, BSTR
domain)
{
 COSERVERINFO si;
 ZeroMemory(&si, sizeof(si));
 COAUTHIDENTITY author_id;
 ZeroMemory(&author_id, sizeof(COAUTHIDENTITY));

 CString shost(host);
 CString suser(user);
 CString spass(pass);
 CString sdomain(domain);

 author_id.Flags =SEC_WINNT_AUTH_IDENTITY_UNICODE;//
SEC_WINNT_AUTH_IDENTITY_ANSI ;SEC_WINNT_AUTH_IDENTITY_ANSI
 author_id.User = (unsigned short*)suser.GetBuffer();//(unsigned
short*)CString(user).GetBuffer();//(unsigned short*)m_sUserName.GetBuffer();
 author_id.UserLength = wcslen((const wchar_t *)author_id.User);
 author_id.Domain = (unsigned short*)sdomain.GetBuffer();//(unsigned
short*)CString(domain).GetBuffer();//(unsigned
short*)m_sDomain.GetBuffer();;
 author_id.DomainLength = wcslen((const wchar_t *)author_id.Domain);
 author_id.Password = (unsigned short*)spass.GetBuffer();//(unsigned
short*)CString(pass).GetBuffer();//(unsigned short*)m_sPassword.GetBuffer();
 author_id.PasswordLength = wcslen((const wchar_t *)author_id.Password);

 COAUTHINFO athn;
    ZeroMemory(&athn, sizeof(COAUTHINFO));
 athn.dwAuthnSvc =
RPC_C_AUTHN_WINNT;//RPC_C_AUTHN_GSS_KERBEROS;//RPC_C_AUTHN_WINNT;
    athn.dwAuthzSvc = RPC_C_AUTHZ_NONE;
 athn.dwAuthnLevel =
RPC_C_AUTHN_LEVEL_NONE;//RPC_C_AUTHN_LEVEL_CALL;//RPC_C_AUTHN_LEVEL_NONE;//
    athn.dwCapabilities = EOAC_NONE;
    athn.dwImpersonationLevel = RPC_C_IMP_LEVEL_IMPERSONATE;
    athn.pAuthIdentityData = &author_id;
    athn.pwszServerPrincName = NULL;

 si.pwszName = shost.GetBuffer();//m_sHostName.GetBuffer();//
L"\\\\mywin2k3";//L"\\\\Chenxingtian-pc";
    si.pAuthInfo = &athn;
    si.dwReserved1 = 0;
    si.dwReserved2 = 0;

 MULTI_QI rgmqi[2];
 ZeroMemory(rgmqi, sizeof(rgmqi));
 rgmqi[0].pIID = &IID_ISubstation;
 rgmqi[1].pIID = &IID_IConnectionPointContainer;

 ISubstation* pSubstation = NULL;
 IConnectionPointContainer* pConnectionPointContainer = NULL;
 IConnectionPoint* pConnectionPoint = NULL;
 DWORD dwAdvise;

 CSecurityDescriptor sd;
    sd.InitializeFromThreadToken();
    HRESULT hRes = CoInitializeSecurity(sd, -1, NULL,
NULL,RPC_C_AUTHN_LEVEL_PKT, RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE,
NULL);//<-return E_ACCESSDENIED
 hRes = CoCreateInstanceEx(CLSID_Substation, NULL, CLSCTX_REMOTE_SERVER,
&si, 2, rgmqi);
 if (hRes == S_OK)
 {
  pSubstation = (ISubstation*)rgmqi[0].pItf;
  pConnectionPointContainer = (IConnectionPointContainer*)rgmqi[1].pItf;
 // pClientSecurity = (IClientSecurity*)rgmqi[2].pItf;
 }
 else
  return S_FALSE;
 pSubstation->SetName(CComBSTR(host));
 hRes = pConnectionPointContainer->FindConnectionPoint(IID_ISubstation,
&pConnectionPoint);

 ISubstation* pConn;
 QueryInterface(IID_ISubstation,(void**)&pConn);
 hRes = pConnectionPoint->Advise((IUnknown*)pConn, &dwAdvise);

 return S_OK;
}