title: JFactory::getUser($id) not working
body: <p>I'm trying to use JFactory::getUser() to get the name and username of a certain user but it returns error!</p>
  
  <p>For example when I write this:</p>
  
  <pre><code>echo JFactory::getUser(645)-&gt;name;
  </code></pre>
  
  <p>it returns this error:</p>
  
  <p>( ! ) SCREAM: Error suppression ignored for
  ( ! ) Fatal error: Call to a member function load() on a non-object in D:\wamp\www\libraries\joomla\user\user.php on line 888</p>
  
  <p>but it works fine when I enter my own id there, and returns my name!</p>
  
  <p>More info:</p>
  
  <p>I use this function in a field type file, and I already used that in another field type file in the same site and in the same way <strong>without any problem</strong>! The difference between these is that: I'm using this in a custom component, but that was used in the com_categories component.</p>