Index: branches/RC/core/kernel/session/session.php
===================================================================
diff -u -N -r10037 -r10098
--- branches/RC/core/kernel/session/session.php	(.../session.php)	(revision 10037)
+++ branches/RC/core/kernel/session/session.php	(.../session.php)	(revision 10098)
@@ -853,17 +853,17 @@
 		$wid = $this->Application->GetVar('m_wid');
 
 		$last_env = $this->getLastTemplateENV($t, Array('m_opener' => 'u'));
-		$last_template = basename($_SERVER['PHP_SELF']).'|'.substr($last_env, strlen(ENV_VAR_NAME) + 1);
+		$last_template = basename($_SERVER['PHP_SELF']).'|'.mb_substr($last_env, mb_strlen(ENV_VAR_NAME) + 1);
 		$this->StoreVar(rtrim('last_template_'.$wid, '_'), $last_template);
 
 		$last_env = $this->getLastTemplateENV($t, null, false);
 
-		$last_template = basename($_SERVER['PHP_SELF']).'|'.substr($last_env, strlen(ENV_VAR_NAME) + 1);
+		$last_template = basename($_SERVER['PHP_SELF']).'|'.mb_substr($last_env, mb_strlen(ENV_VAR_NAME) + 1);
 		$this->StoreVar(rtrim('last_template_popup_'.$wid, '_'), $last_template);
 
 		// save other last... variables for mistical purposes (customizations may be)
 		$this->StoreVar('last_url', $_SERVER['REQUEST_URI']); // needed by ord:StoreContinueShoppingLink
-		$this->StoreVar('last_env', substr($last_env, strlen(ENV_VAR_NAME)+1));
+		$this->StoreVar('last_env', mb_substr($last_env, mb_strlen(ENV_VAR_NAME)+1));
 
 		// save last_template in persistant session
 		if (!$wid) {