--- taxonomy.module	2008-06-28 21:51:02.000000000 +0200
+++ /home/dereine/public_html/drupal7/modules/taxonomy/taxonomy.module	2008-07-13 22:45:06.000000000 +0200
@@ -992,8 +992,8 @@ function taxonomy_vocabulary_load($vid) 
     }
   }
 
-  // Return NULL if this vocabulary does not exist.
-  return !empty($vocabularies[$vid]) ? $vocabularies[$vid] : NULL;
+  // Return false if this vocabulary does not exist.
+  return !empty($vocabularies[$vid]) ? $vocabularies[$vid] : false;
 }
 
 /**