title: Symfony2: default locale not translated in prod env
body: <p>I have set up my website translation on Symfony2 with JMSTranslationBundle and JMSI18nRoutingBundle. The default locale is "en", and I have successfully translated text to "fr".</p>
  
  <p>In dev environment, everything is working great, I get the right translations in <strong>/en</strong> and <strong>/fr</strong> pages, but in prod environment, only <strong>/fr</strong> is correctly translated. In <strong>/en</strong> pages I only see the translations names, ie <strong>text.submit</strong>.</p>
  
  <p>I'm using the <strong>desc</strong> filter as default translation, so I do not have xliff files for english.</p>
  
  <p>Any idea what prevents the default translation from being used in <strong>prod</strong> environment?</p>
  
  <p>Btw, I have cleared the cache ;)</p>