title: Magento Shipping Method Rate returning NULL
body: <p>I created a new shipping method in Magento to use with the Onepage Checkout. The method appears on the front end and is defined, however whenever trying to retrieve the rates, it returns NULL. Specifically in <code>Mage/Sales/Model/Quote.php</code>, <code>$method</code> returns my method, but <code>$rate = null</code>.</p>
  
  <p>Module: </p>
  
  <pre><code>protected $_code = 'module_shipping';
  
  public function collectRates(Mage_Shipping_Model_Rate_Request $request)
  {
      $result = Mage::getModel('shipping/rate_result');
  
      $result-&gt;append($this-&gt;_getMyShippingShippingRate());
  
      return $result;
  }
  
  protected function _getMyShippingShippingRate()
  {
      $rate = Mage::getModel('shipping/rate_result_method');
  
      $rate-&gt;setCarrier($this-&gt;_code);
  
      $rate-&gt;setCarrierTitle($this-&gt;getConfigData('title'));
  
      $rate-&gt;setMethod('my_ship_fn');
      $rate-&gt;setMethodTitle('A New Method');
  
      $rate-&gt;setPrice(0);
      $rate-&gt;setCost(0);
  
      return $rate;
  }
  
  public function getAllowedMethods()
  {
      return array(
          'my_ship_fn' =&gt; 'A New Method',
      );
  }
  </code></pre>
  
  <p>Config.xml </p>
  
  <pre><code>&lt;default&gt;
      &lt;carriers&gt;
          &lt;module_shipping&gt;
              &lt;active&gt;1&lt;/active&gt;
              &lt;model&gt;company_retailshipping/carrier_myshippingfn&lt;/model&gt;
              &lt;title&gt;A New Method&lt;/title&gt;
              &lt;sort_order&gt;10&lt;/sort_order&gt;
              &lt;sallowspecific&gt;0&lt;/sallowspecific&gt;
          &lt;/module_shipping&gt;
      &lt;/carriers&gt;
  &lt;/default&gt;
  </code></pre>