event notifications not received as described

HRESULT STDMETHODCALLTYPE Invoke(
{
//omitted parameters

// The riid parameter is always supposed to be IID_NULL
	    if (riid != IID_NULL)
		    return DISP_E_UNKNOWNINTERFACE;

if (pDispParams) //DISPID dispIdMember
	{
		switch (dispIdMember) {
		case 1:
			return Event_one();
		case 2:
			return Event_two();
		case 3:
			return Event_three();
		default:
			return E_NOTIMPL;
		}
	}
	return E_NOTIMPL;
}

STDMETHOD (QueryInterface)(
//omitted parameters
{
	if (iid == IID_IUnknown || iid == __uuidof(IEvents))
	{
		*ppvObject = (IEvents *)this;
	} else {
		*ppvObject = NULL;
		return E_NOINTERFACE;
	}
	m_dwRefCount++;
	return S_OK;
};

methods:
    [id(0x00000002)]
    HRESULT Event_one();

//omitted


if (pDispParams) //DISPID dispIdMember
        {
            switch (dispIdMember) {
            case 2:
                    return Event_one();

//omitted