title: Symfony2 ParamConverter not associated with @Annotation (cache must be cleared after any file change)
body: <p>I have a Controller that uses Annotations for Route, Method, Template and ParamConverter.<br>
  If I make any change to the file (even a whitespace change or comment) on the next page load the following error occurs</p>
  
  <pre><code>Cannot import resource "/home/sites/MySite/src/Acme/Bundle/MyBundle/Controller/" from "/home/sites/MySite/app/config/routing.yml".
  
  FileLoaderLoadException: Cannot import resource "/home/sites/MySite/src/Acme/Bundle/MyBundle/Controller/" from "/home/sites/MySite/app/config/routing.yml"
  
  AnnotationException: [Semantical Error] The class "Sensio\Bundle\FrameworkExtraBundle\Configuration\ParamConverter" is not annotated with @Annotation. Are you sure this class can be used as annotation? If so, then you need to add @Annotation to the _class_ doc comment of "Sensio\Bundle\FrameworkExtraBundle\Configuration\ParamConverter". If it is indeed no annotation, then you need to add @IgnoreAnnotation("ParamConverter") to the _class_ doc comment of method Acme\Bundle\MyBundle\Controller\DefaultController::viewAction().
  </code></pre>
  
  <p>If I clear my cache, then it will work again, but only until I make another change, then it happens again.
  It looks like it's hitting an issue when reading in the annotation info for config, but I can't understand why it works/doesn't work when the change isn't actually made to any annotation.</p>