title: Routing in CakePHP 1.3.3 has suddenly stopped working for one folder (beforeFilter issues?)
body: <p>We've had an application running on CakePHP 1.3.3 for years without a single hitch, but randomly it's started saying <em>"The requested address /task_scheduler/task_scheduler_mailouts was not found on this server."</em> - but it's only effecting this. Everything else running on that server (including other CakePHP applications) are fine.</p>
  
  <p>When I enable debug in core.php, I get the following error messages:</p>
  
  <pre><code>Notice (8): Undefined variable: currentUser [APP\views\themed\default\layouts\default.ctp, line 50]
  
  Error: The Behavior file app\models\behaviors\null.php can not be found or does not exist.
  
  Error: Create the class below in file: app\models\behaviors\null.php
  
  &lt;?php
  class NullBehavior extends ModelBehavior {
  
  }
  ?&gt;
  </code></pre>
  
  <p>All of the files are present in /task_scheduler/task_scheduler_mailouts and the currentUser variable is working without any problems on the other pages. currentUser is set in the <code>beforeFilter()</code> function in app_controller.php which as far as I know is used for every single page.</p>
  
  <pre><code>function beforeFilter() {
      ...
      $currentUser = ClassRegistry::init('WfEmployee')-&gt;getNetworkUser();
      ...
  }
  </code></pre>
  
  <p><em>(update)</em> if I hardcode the $currentUser variable I still get the not set notice. I don't think the beforeFilter() function is even running.</p>
  
  <p>Any ideas as to what could have suddenly caused this error please? Thank you.</p>