title: Magento getSingleton() vs getModel() issue
body: <p>I want to loop over an array of product IDs in Magento. In the loop I am displaying some custom attributes of the products as:</p>
  
  <pre><code>foreach ($products as $product) {
     $model = Mage::getSingleton('catalog/product')-&gt;load($product['id']);
     echo '&lt;br&gt;' . $model-&gt;getCredits();
  }
  </code></pre>
  
  <p>Problem is that if the value of <code>getCredits()</code> for the first item is <code>true</code> then all the subsequent items show <code>true</code> even if they do not have the value <code>true</code>.</p>
  
  <p>But when I use <code>Mage::getModel()</code> instead of <code>Mage::getSingleton()</code>, the attribute values are displayed correct.</p>
  
  <p>Can anyone please explain this difference?</p>