diff --git a/change_log.txt b/change_log.txt
index 87cfb356..f3f19213 100644
--- a/change_log.txt
+++ b/change_log.txt
@@ -1,4 +1,6 @@
 ===== SVN trunk  =====
+- bugfix mb_str_replace in replace and escape modifiers work with utf8
+
 31/12/2010
 - bugfix dynamic configuration of $debugging_crtl did not work
 - bugfix default value of $config_read_hidden changed to false
diff --git a/libs/plugins/modifier.escape.php b/libs/plugins/modifier.escape.php
index dae59268..37bc0e30 100644
--- a/libs/plugins/modifier.escape.php
+++ b/libs/plugins/modifier.escape.php
@@ -22,25 +22,6 @@
  */
 function smarty_modifier_escape($string, $esc_type = 'html', $char_set = SMARTY_RESOURCE_CHAR_SET)
 {
-    if (!function_exists('mb_str_replace')) {
-        // simulate the missing PHP mb_str_replace function
-        function mb_str_replace($needles, $replacements, $haystack)
-        {
-            $rep = (array)$replacements;
-            foreach ((array)$needles as $key => $needle) {
-                $replacement = $rep[$key];
-                $needle_len = mb_strlen($needle);
-                $replacement_len = mb_strlen($replacement);
-                $pos = mb_strpos($haystack, $needle, 0);
-                while ($pos !== false) {
-                    $haystack = mb_substr($haystack, 0, $pos) . $replacement
-                     . mb_substr($haystack, $pos + $needle_len);
-                    $pos = mb_strpos($haystack, $needle, $pos + $replacement_len);
-                } 
-            } 
-            return $haystack;
-        } 
-    } 
     switch ($esc_type) {
         case 'html':
             return htmlspecialchars($string, ENT_QUOTES, $char_set);
@@ -85,12 +66,8 @@ function smarty_modifier_escape($string, $esc_type = 'html', $char_set = SMARTY_
             return strtr($string, array('\\' => '\\\\', "'" => "\\'", '"' => '\\"', "\r" => '\\r', "\n" => '\\n', '</' => '<\/'));
 
         case 'mail': 
-            // safe way to display e-mail address on a web page
-            if (function_exists('mb_substr')) {
-                return mb_str_replace(array('@', '.'), array(' [AT] ', ' [DOT] '), $string);
-            } else {
-                return str_replace(array('@', '.'), array(' [AT] ', ' [DOT] '), $string);
-            } 
+          require_once(SMARTY_PLUGINS_DIR . 'shared.mb_str_replace.php');
+          return smarty_mb_str_replace(array('@', '.'), array(' [AT] ', ' [DOT] '), $string);
 
         case 'nonstd': 
             // escape non-standard chars, such as ms document quotes
diff --git a/libs/plugins/modifier.replace.php b/libs/plugins/modifier.replace.php
index 98195ffb..0636a191 100644
--- a/libs/plugins/modifier.replace.php
+++ b/libs/plugins/modifier.replace.php
@@ -22,30 +22,8 @@
  */
 function smarty_modifier_replace($string, $search, $replace)
 {
-    if (!function_exists('mb_str_replace')) {
-        // simulate the missing PHP mb_str_replace function
-        function mb_str_replace($needles, $replacements, $haystack)
-        {
-            $rep = (array)$replacements;
-            foreach ((array)$needles as $key => $needle) {
-                $replacement = $rep[$key];
-                $needle_len = mb_strlen($needle);
-                $replacement_len = mb_strlen($replacement);
-                $pos = mb_strpos($haystack, $needle, 0);
-                while ($pos !== false) {
-                    $haystack = mb_substr($haystack, 0, $pos) . $replacement
-                     . mb_substr($haystack, $pos + $needle_len);
-                    $pos = mb_strpos($haystack, $needle, $pos + $replacement_len);
-                } 
-            } 
-            return $haystack;
-        } 
-    } 
-    if (function_exists('mb_substr')) {
-        return mb_str_replace($search, $replace, $string);
-    } else {
-        return str_replace($search, $replace, $string);
-    } 
+    require_once(SMARTY_PLUGINS_DIR . 'shared.mb_str_replace.php');
+    return smarty_mb_str_replace($search, $replace, $string);
 } 
 
 ?>
\ No newline at end of file
diff --git a/libs/plugins/shared.mb_str_replace.php b/libs/plugins/shared.mb_str_replace.php
new file mode 100644
index 00000000..8bc156f0
--- /dev/null
+++ b/libs/plugins/shared.mb_str_replace.php
@@ -0,0 +1,38 @@
+<?php
+
+if(!function_exists('smarty_mb_str_replace')) {
+  function smarty_mb_str_replace($search, $replace, $subject, &$count=0) { 
+      if (!is_array($search) && is_array($replace)) { 
+          return false; 
+      } 
+      if (is_array($subject)) { 
+          // call mb_replace for each single string in $subject 
+          foreach ($subject as &$string) { 
+              $string = &smarty_mb_str_replace($search, $replace, $string, $c); 
+              $count += $c; 
+          } 
+      } elseif (is_array($search)) { 
+          if (!is_array($replace)) { 
+              foreach ($search as &$string) { 
+                  $subject = smarty_mb_str_replace($string, $replace, $subject, $c); 
+                  $count += $c; 
+              } 
+          } else { 
+              $n = max(count($search), count($replace)); 
+              while ($n--) { 
+                  $subject = smarty_mb_str_replace(current($search), current($replace), $subject, $c); 
+                  $count += $c; 
+                  next($search); 
+                  next($replace); 
+              } 
+          } 
+      } else { 
+          $parts = mb_split(preg_quote($search), $subject); 
+          $count = count($parts)-1; 
+          $subject = implode($replace, $parts); 
+      } 
+      return $subject; 
+  }
+}
+
+?>
\ No newline at end of file