I2COpen is unable to obtain handle

I am trying to access the I2C bus. Here is my code:

void TestI2C()
{

	HANDLE hParent;
	HANDLE hI2C;
    hParent = CreateFile(L"BUS1:", 0, 0, NULL, 0, 0, NULL);
    if (hParent == INVALID_HANDLE_VALUE)
    {
		_tprintf(_T("Error opening parent\n"));
        hParent = NULL;
		goto error;
    }
	for (int i=0; i<5; i++)
	{
		DWORD i2cDeviceID = SOCGetI2CDeviceByBus(i);
		_tprintf(_T("Bus: %d, Device ID: %d\n"), i, i2cDeviceID);
		if (i2cDeviceID == -1)
			continue;
		hI2C = I2COpen(i2cDeviceID);
		if (hI2C == NULL)
		{
			_tprintf(_T("hI2C (%d) is NULL\n"), i2cDeviceID);
		}
		else
		{
			_tprintf(_T("hI2C (%d) is %d\n"), i2cDeviceID, hI2C);
			break;
		}
	}
	if (hI2C == NULL)
	{
		goto error;
	}
error:
	if (hI2C != NULL)
	{
		I2CClose(hI2C);
	}
	if (hParent != NULL)
	{
		CloseHandle(hParent);
	}
}

When I get a valid device ID (when 1<=i<=3) and I2COpen is called the return value is always NULL.  Can anyone tell me what I'm doing wrong?

David