diff -aburN inc.original/common.php inc/common.php
--- inc.original/common.php	2009-02-14 13:13:25.000000000 +0100
+++ inc/common.php	2009-07-05 19:21:35.000000000 +0200
@@ -281,7 +281,7 @@
   }
   //we only save on show and existing wiki documents
   $file = wikiFN($ID);
-  if($ACT != 'show' || !@file_exists($file)){
+  if($ACT != 'show' || !@file_exists($file) || auth_quickaclcheck($ID) < AUTH_READ){
     $_SESSION[DOKU_COOKIE]['bc'] = $crumbs;
     return $crumbs;
   }
diff -aburN inc.original/parser/xhtml.php inc/parser/xhtml.php
--- inc.original/parser/xhtml.php	2009-02-14 13:13:25.000000000 +0100
+++ inc/parser/xhtml.php	2009-07-05 19:28:19.000000000 +0200
@@ -488,7 +488,7 @@
         resolve_pageid(getNS($ID),$id,$exists);
         $name = $this->_getLinkTitle($name, $default, $isImage, $id, $linktype);
         if ( !$isImage ) {
-            if ( $exists ) {
+            if ( $exists && (auth_quickaclcheck($id) >= AUTH_READ) ) {
                 $class='wikilink1';
             } else {
                 $class='wikilink2';
diff -aburN inc.original/parserutils.php inc/parserutils.php
--- inc.original/parserutils.php	2009-02-14 13:13:25.000000000 +0100
+++ inc/parserutils.php	2009-07-05 19:26:24.000000000 +0200
@@ -617,7 +617,7 @@
  * @author Andreas Gohr <andi@splitbrain.org>
  */
 function p_get_first_heading($id, $render=true){
-  return p_get_metadata($id,'title',$render);
+  return (auth_quickaclcheck($id) >= AUTH_READ) ? p_get_metadata($id,'title',$render) : null;
 }
 
 /**
diff -aburN inc.original/template.php inc/template.php
--- inc.original/template.php	2009-07-05 18:29:01.000000000 +0200
+++ inc/template.php	2009-07-05 19:33:55.000000000 +0200
@@ -874,7 +874,7 @@
 
     // output
     echo $sep;
-    if($exists){
+    if($exists && (auth_quickaclcheck($page) >= AUTH_READ)){
       $title = useHeading('navigation') ? p_get_first_heading($page) : $page;
       if(!$title) $title = $parts[$i];
       tpl_link(wl($page),hsc($title),'title="'.$page.'"');
@@ -888,7 +888,7 @@
   $page = $part.$parts[$i];
   if($page == $conf['start']) return;
   echo $sep;
-  if(page_exists($page)){
+  if(page_exists($page) && (auth_quickaclcheck($page) >= AUTH_READ)){
     $title = useHeading('navigation') ? p_get_first_heading($page) : $page;
     if(!$title) $title = $parts[$i];
     tpl_link(wl($page),hsc($title),'title="'.$page.'"');