--- devel_demo.module	2010-02-07 18:41:56.000000000 +0300
+++ devel_demo.module.new	2011-01-16 14:27:56.000000000 +0300
@@ -110,8 +110,7 @@ function devel_demo_page() {
   $content = theme('item_list', array('items' => $advanced_demos));
   $output .= '<h2 class="title">'. t('Advanced') .'</h2>'. $content;
 
-  $path = drupal_get_path('module', 'devel') .'/FirePHPCore/lib/FirePHPCore/fb.php';
-  if (file_exists($path)) {
+  if (function_exists('fb')) {
     $firephp_demos = array(
       l('dfb()', 'admin/config/development/devel_demo/dfb'),
       l('dfb()', 'admin/config/development/devel_demo/dfb_severity') .' '. t('using various severity levels'),