CoCreateInstance - The COM+ registry database detected a system error

In a small test project I have this code:

HRESULT hr = CoCreateInstance(CLSID_DOMDocument, NULL, CLSCTX_ALL, __uuidof( IXMLDOMDocument ), ( void ** ) & m_pDoc);
if ( hr != S_OK )
{
  throw "MSXML DOM Document could not be created";
}

This compiles and runs without problems. In another project the same code fails with:

hr = 0x80110474 The COM+ registry database detected a system error

Both projects are C++ compiled using Visual Studio 2010. I've been through and compared settings side-by-side between the two projects to try and determine what difference could be causing this issue. So far I can see no reason why the test project runs and the other project fails.

Edit - Full sample code listing:

#include "stdafx.h"
#include <atlbase.h>
#include <atlconv.h>
#include "MsXml.h"
int _tmain(int argc, _TCHAR* argv[])
{
    IXMLDOMDocument* m_pDoc = NULL;
    if(FAILED(CoInitializeEx( 0, COINIT_MULTITHREADED )))
      if(FAILED(CoInitializeEx( 0, COINIT_APARTMENTTHREADED )))
        throw "Could not initialize COM";
    HRESULT hr = CoCreateInstance( CLSID_DOMDocument, NULL, CLSCTX_ALL, __uuidof( IXMLDOMDocument ), ( void ** ) & m_pDoc);
    if ( hr != S_OK )
      throw "MSXML DOM Document could not be created";
    return 0;
}

Found a solution, although not ideal it solved the problem. I created a new project and manually imported the settings.