SoapConnector 无法创建成功，com初始化没有问题。请教？

我在程序中先进行com初始化，是可以成功通过的。
C/C++ code

#import "msxml4.dll"  
#import "C:\Program Files\Common Files\MSSoap\Binaries\mssoap30.dll" exclude("IStream", "IErrorInfo", "ISequentialStream", "_LARGE_INTEGER", "_ULARGE_INTEGER", "tagSTATSTG ", "_FILETIME ") 
using namespace MSXML2;
using   namespace   MSSOAPLib30; 

//......................
//.....................

HRESULT hr = CoInitialize(NULL);
if(FAILED(hr))
AfxMessageBox("CoInitialize FAILED.\n");

但是后面的创建句柄失败，不解。
C/C++ code

HRESULT   hr; 
ISoapConnectorPtr   SoapConnector; 
//创建SoapConnector类的对象 
        hr = SoapConnector.CreateInstance(__uuidof(HttpConnector30));   
        if(FAILED(hr)) {
            TRACE1("SoapConnector.CreateInstance FAILED. error  code - %d\n", GetLastError());
        }

请高人指点一下。

下面创建对象的代码放多点 怎么感觉这么怪异
ISoapConnectorPtr SoapConnector; 
//创建SoapConnector类的对象 
  hr = SoapConnector.CreateInstance(__uuidof(HttpConnector30));

第一个地方的 对象怎么出来的 第二个地方CreateInstance没这样的参数吧