Index: modules/taxonomy/taxonomy.admin.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/taxonomy/taxonomy.admin.inc,v
retrieving revision 1.116
diff -u -p -r1.116 taxonomy.admin.inc
--- modules/taxonomy/taxonomy.admin.inc	20 Nov 2010 06:49:47 -0000	1.116
+++ modules/taxonomy/taxonomy.admin.inc	19 Feb 2011 18:17:09 -0000
@@ -147,7 +147,7 @@ function taxonomy_form_vocabulary($form,
   $form['machine_name'] = array(
     '#type' => 'machine_name',
     '#default_value' => $vocabulary->machine_name,
-    '#maxlength' => 21,
+    '#maxlength' => 255,
     '#machine_name' => array(
       'exists' => 'taxonomy_vocabulary_machine_name_load',
     ),