diff --git a/admin/history.php b/admin/history.php
index 02b321055..222deaaf1 100644
--- a/admin/history.php
+++ b/admin/history.php
@@ -116,7 +116,8 @@ if (isset($_POST['submit']))
 
   $search['fields']['display_thumbnail'] = $_POST['display_thumbnail'];
   // Display choise are also save to one cookie
-  pwg_set_cookie_var('history_display_thumbnail', $_POST['display_thumbnail']);
+  $cookie_val = ($_POST['display_thumbnail']!=$display_thumbnails[2] and in_array($_POST['display_thumbnail'], $display_thumbnails)) ? $_POST['display_thumbnail']:null;
+  pwg_set_cookie_var('history_display_thumbnail', $cookie_val, strtotime('+1 month') );
 
   // TODO manage inconsistency of having $_POST['image_id'] and
   // $_POST['filename'] simultaneously
diff --git a/include/common.inc.php b/include/common.inc.php
index 1ddebfc9b..a8f661dca 100644
--- a/include/common.inc.php
+++ b/include/common.inc.php
@@ -223,6 +223,7 @@ if ($conf['gallery_locked'])
     @header('Retry-After: 900');
     echo l10n('gallery_locked_message')
       .'<a href="'.get_absolute_root_url(false).'identification.php">.</a>';
+    echo str_repeat( ' ', 512); //IE6 doesn't error output if below a size
     exit();
   }
 }
diff --git a/include/functions_cookie.inc.php b/include/functions_cookie.inc.php
index 159a5b538..66b66221f 100644
--- a/include/functions_cookie.inc.php
+++ b/include/functions_cookie.inc.php
@@ -36,15 +36,15 @@ function cookie_path()
   {
     // mod_rewrite is activated for upper level directories. we must set the
     // cookie to the path shown in the browser otherwise it will be discarded.
-    if 
-      ( 
+    if
+      (
         isset($_SERVER['PATH_INFO']) and !empty($_SERVER['PATH_INFO']) and
         ($_SERVER['REDIRECT_URL'] !== $_SERVER['PATH_INFO']) and
         (substr($_SERVER['REDIRECT_URL'],-strlen($_SERVER['PATH_INFO']))
             == $_SERVER['PATH_INFO'])
       )
     {
-      $scr = substr($_SERVER['REDIRECT_URL'], 0, 
+      $scr = substr($_SERVER['REDIRECT_URL'], 0,
         strlen($_SERVER['REDIRECT_URL'])-strlen($_SERVER['PATH_INFO']));
     }
     else
@@ -64,7 +64,7 @@ function cookie_path()
   {
     $scr .= '/';
   }
-  
+
   if ( substr(PHPWG_ROOT_PATH,0,3)=='../')
   { // this is maybe a plugin inside pwg directory
     // TODO - what if it is an external script outside PWG ?
@@ -87,12 +87,20 @@ function cookie_path()
  * @return boolean true on success
  * @see pwg_get_cookie_var
  */
-function pwg_set_cookie_var($var, $value)
+function pwg_set_cookie_var($var, $value, $expire=null)
 {
-  $_COOKIE['pwg_'.$var] = $value;
-  return
-    setcookie('pwg_'.$var, $value, 
-      strtotime('+10 years'), cookie_path());
+  if ($value==null or $expire===0)
+  {
+    unset($_COOKIE['pwg_'.$var]);
+    return setcookie('pwg_'.$var, false, 0, cookie_path());
+
+  }
+  else
+  {
+    $_COOKIE['pwg_'.$var] = $value;
+    $expire = is_numeric($expire) ? $expire : strtotime('+10 years');
+    return setcookie('pwg_'.$var, $value, $expire, cookie_path());
+  }
 }
 
 /**
diff --git a/include/functions_html.inc.php b/include/functions_html.inc.php
index ca07a1e16..2b3994aa8 100644
--- a/include/functions_html.inc.php
+++ b/include/functions_html.inc.php
@@ -585,16 +585,17 @@ function access_denied()
       get_root_url().'identification.php?redirect='
       .urlencode(urlencode($_SERVER['REQUEST_URI']));
 
+  set_status_header(401);
   if ( isset($user) and !is_a_guest() )
   {
     echo '<div style="text-align:center;">'.l10n('access_forbiden').'<br />';
     echo '<a href="'.get_root_url().'identification.php">'.l10n('identification').'</a>&nbsp;';
     echo '<a href="'.make_index_url().'">'.l10n('home').'</a></div>';
+    echo str_repeat( ' ', 512); //IE6 doesn't error output if below a size
     exit();
   }
   else
   {
-    set_status_header(401);
     redirect_html($login_url);
   }
 }
@@ -677,7 +678,7 @@ $btrace_msg
 </pre>\n";
 
   @set_status_header(500);
-  echo $display.str_repeat( ' ', 300); //IE doesn't error output if below a size
+  echo $display.str_repeat( ' ', 300); //IE6 doesn't error output if below a size
 
   if ( function_exists('ini_set') )
   {// if possible turn off error display (we display it)
@@ -754,6 +755,7 @@ function set_status_header($code, $text='')
       case 403: $text='Forbidden';break;
       case 404: $text='Not found';break;
       case 500: $text='Server error';break;
+      case 501: $text='Not implemented';break;
       case 503: $text='Service unavailable';break;
     }
   }
diff --git a/include/functions_notification.inc.php b/include/functions_notification.inc.php
index 259a34613..32d3ed9c7 100644
--- a/include/functions_notification.inc.php
+++ b/include/functions_notification.inc.php
@@ -35,7 +35,7 @@
  *
  * @return string sql where
  */
-function get_std_sql_where_restrict_filter($prefix_condition, $force_one_condition = false)
+function get_std_sql_where_restrict_filter($prefix_condition, $img_field='ic.image_id', $force_one_condition = false)
 {
   return get_sql_condition_FandF
           (
@@ -43,7 +43,7 @@ function get_std_sql_where_restrict_filter($prefix_condition, $force_one_conditi
               (
                 'forbidden_categories' => 'ic.category_id',
                 'visible_categories' => 'ic.category_id',
-                'visible_images' => 'ic.image_id'
+                'visible_images' => $img_field
               ),
             $prefix_condition,
             $force_one_condition
@@ -89,7 +89,7 @@ function custom_notification_query($action, $type, $start, $end)
   FROM '.IMAGES_TABLE.' INNER JOIN '.IMAGE_CATEGORY_TABLE.' AS ic ON image_id = id
   WHERE date_available > \''.$start.'\'
     AND date_available <= \''.$end.'\'
-      '.get_std_sql_where_restrict_filter('AND').'
+      '.get_std_sql_where_restrict_filter('AND', 'id').'
 ;';
       break;
     case 'updated_categories':
@@ -97,7 +97,7 @@ function custom_notification_query($action, $type, $start, $end)
   FROM '.IMAGES_TABLE.' INNER JOIN '.IMAGE_CATEGORY_TABLE.' AS ic ON image_id = id
   WHERE date_available > \''.$start.'\'
     AND date_available <= \''.$end.'\'
-      '.get_std_sql_where_restrict_filter('AND').'
+      '.get_std_sql_where_restrict_filter('AND', 'id').'
 ;';
       break;
     case 'new_users':
@@ -434,13 +434,13 @@ function get_recent_post_dates($max_dates, $max_elements, $max_cats)
 {
   global $conf, $user;
 
-  $where_sql = get_std_sql_where_restrict_filter('WHERE', true);
+  $where_sql = get_std_sql_where_restrict_filter('WHERE', 'i.id', true);
 
   $query = '
 SELECT date_available,
       COUNT(DISTINCT id) nb_elements,
       COUNT(DISTINCT category_id) nb_cats
-  FROM '.IMAGES_TABLE.' INNER JOIN '.IMAGE_CATEGORY_TABLE.' AS ic ON id=image_id
+  FROM '.IMAGES_TABLE.' i INNER JOIN '.IMAGE_CATEGORY_TABLE.' AS ic ON id=image_id
   '.$where_sql.'
   GROUP BY date_available
   ORDER BY date_available DESC
@@ -459,7 +459,7 @@ SELECT date_available,
     { // get some thumbnails ...
       $query = '
 SELECT DISTINCT id, path, name, tn_ext, file
-  FROM '.IMAGES_TABLE.' INNER JOIN '.IMAGE_CATEGORY_TABLE.' AS ic ON id=image_id
+  FROM '.IMAGES_TABLE.' i INNER JOIN '.IMAGE_CATEGORY_TABLE.' AS ic ON id=image_id
   '.$where_sql.'
     AND date_available="'.$dates[$i]['date_available'].'"
     AND tn_ext IS NOT NULL
diff --git a/include/ws_core.inc.php b/include/ws_core.inc.php
index cc1c1c756..24f10f114 100644
--- a/include/ws_core.inc.php
+++ b/include/ws_core.inc.php
@@ -35,7 +35,7 @@ define( 'WS_PARAM_ACCEPT_ARRAY',  0x010000 );
 define( 'WS_PARAM_FORCE_ARRAY',   0x030000 );
 define( 'WS_PARAM_OPTIONAL',      0x040000 );
 
-define( 'WS_ERR_INVALID_METHOD',  1001 );
+define( 'WS_ERR_INVALID_METHOD',  501 );
 define( 'WS_ERR_MISSING_PARAM',   1002 );
 define( 'WS_ERR_INVALID_PARAM',   1003 );
 
@@ -47,12 +47,15 @@ define( 'WS_XML_CONTENT', 'content_xml_');
  */
 class PwgError
 {
-  var $_code;
-  var $_codeText;
+  private $_code;
+  private $_codeText;
 
   function PwgError($code, $codeText)
   {
-    set_status_header($code, $codeText);
+    if ($code>=400 and $code<600)
+    {
+      set_status_header($code, $codeText);
+    }
 
     $this->_code = $code;
     $this->_codeText = $codeText;
@@ -80,7 +83,7 @@ class PwgNamedArray
    * @param xmlAttributes array of sub-item attributes that will be encoded as
    *      xml attributes instead of xml child elements
    */
-  function PwgNamedArray(&$arr, $itemName, $xmlAttributes=array() )
+  function PwgNamedArray($arr, $itemName, $xmlAttributes=array() )
   {
     $this->_content = $arr;
     $this->_itemName = $itemName;
@@ -133,52 +136,6 @@ class PwgNamedStruct
 }
 
 
-/**
- * Replace array_walk_recursive()
- *
- * @category    PHP
- * @package     PHP_Compat
- * @link        http://php.net/function.array_walk_recursive
- * @author      Tom Buskens <ortega@php.net>
- * @author      Aidan Lister <aidan@php.net>
- * @version     $Revision$
- * @since       PHP 5
- * @require     PHP 4.0.6 (is_callable)
- */
-if (!function_exists('array_walk_recursive')) {
-    function array_walk_recursive(&$input, $funcname)
-    {
-        if (!is_callable($funcname)) {
-            if (is_array($funcname)) {
-                $funcname = $funcname[0] . '::' . $funcname[1];
-            }
-            user_error('array_walk_recursive() Not a valid callback ' . $user_func,
-                E_USER_WARNING);
-            return;
-        }
-
-        if (!is_array($input)) {
-            user_error('array_walk_recursive() The argument should be an array',
-                E_USER_WARNING);
-            return;
-        }
-
-        $args = func_get_args();
-
-        foreach ($input as $key => $item) {
-            if (is_array($item)) {
-                array_walk_recursive($item, $funcname, $args);
-                $input[$key] = $item;
-            } else {
-                $args[0] = &$item;
-                $args[1] = &$key;
-                call_user_func_array($funcname, $args);
-                $input[$key] = $item;
-            }
-        }
-    }
-}
-
 /**
  * Abstract base class for request handlers.
  */
@@ -209,7 +166,7 @@ class PwgResponseEncoder
    * returns true if the parameter is a 'struct' (php array type whose keys are
    * NOT consecutive integers starting with 0)
    */
-  function is_struct(&$data)
+  static function is_struct(&$data)
   {
     if (is_array($data) )
     {
@@ -225,7 +182,7 @@ class PwgResponseEncoder
    * removes all XML formatting from $response (named array, named structs, etc)
    * usually called by every response encoder, except rest xml.
    */
-  function flattenResponse(&$response)
+  static function flattenResponse(&$response)
   {
     PwgResponseEncoder::_mergeAttributesAndContent($response);
     PwgResponseEncoder::_removeNamedArray($response);
@@ -239,7 +196,7 @@ class PwgResponseEncoder
     PwgResponseEncoder::_mergeAttributesAndContent($response);
   }
 
-  /*private*/ function _remove_named_callback(&$value, $key)
+  private static function _remove_named_callback(&$value, $key)
   {
     do
     {
@@ -251,7 +208,7 @@ class PwgResponseEncoder
     while ($changed);
   }
 
-  /*private*/ function _mergeAttributesAndContent(&$value)
+  private static function _mergeAttributesAndContent(&$value)
   {
     if ( !is_array($value) )
       return;
@@ -310,7 +267,7 @@ class PwgResponseEncoder
     return $ret;
   }
 
-  /*private*/ function _removeNamedArray(&$value)
+  private static function _removeNamedArray(&$value)
   {
     if ( strtolower( get_class($value) ) =='pwgnamedarray')
     {
@@ -320,7 +277,7 @@ class PwgResponseEncoder
     return 0;
   }
 
-  /*private*/ function _removeNamedStruct(&$value)
+  private static function _removeNamedStruct(&$value)
   {
     if ( strtolower( get_class($value) ) =='pwgnamedstruct')
     {
@@ -388,9 +345,7 @@ Request format: ".@$this->_requestFormat." Response format: ".@$this->_responseF
 
     if ( is_null($this->_requestHandler) )
     {
-      $this->sendResponse(
-        new PwgError(400, 'Unknown request format')
-        );
+      $this->sendResponse( new PwgError(400, 'Unknown request format') );
       return;
     }
 
@@ -583,7 +538,7 @@ Request format: ".@$this->_requestFormat." Response format: ".@$this->_responseF
   /**
    * WS reflection method implementation: lists all available methods
    */
-  /*static*/ function ws_getMethodList($params, &$service)
+  static function ws_getMethodList($params, &$service)
   {
     return array('methods' => new PwgNamedArray( array_keys($service->_methods),'method' ) );
   }
@@ -591,7 +546,7 @@ Request format: ".@$this->_requestFormat." Response format: ".@$this->_responseF
   /**
    * WS reflection method implementation: gets information about a given method
    */
-  /*static*/ function ws_getMethodDetails($params, &$service)
+  static function ws_getMethodDetails($params, &$service)
   {
     $methodName = $params['methodName'];
     if (!$service->hasMethod($methodName))