diff -r b8db9a7946fc -r 10076b28194b includes/pageprocess.php
--- a/includes/pageprocess.php	Mon Apr 13 12:05:46 2009 -0400
+++ b/includes/pageprocess.php	Mon Apr 13 12:32:28 2009 -0400
@@ -837,6 +837,7 @@
   function protect_page($protection_level, $reason)
   {
     global $db, $session, $paths, $template, $plugins; // Common objects
+    global $cache;
     
     // Validate permissions
     if ( !$this->perms->get_permissions('protect') )
@@ -902,6 +903,8 @@
     if ( !$q )
       $db->die_json();
     
+    $cache->purge('page_meta');
+    
     return array(
       'success' => true
       );