Index: upload_element.pages.inc
===================================================================
--- upload_element.pages.inc	(revision 793)
+++ upload_element.pages.inc	(working copy)
@@ -118,6 +118,9 @@
       }
       $element['#messages'] = theme('status_messages');
       $output = drupal_render($element);
+      // For some reason, file uploads don't like drupal_json() with its manual
+      // setting of the text/javascript HTTP header. So use this one instead.
+      $GLOBALS['devel_shutdown'] = false;
       print drupal_to_js(array('data' => $output));
       exit();
     }