Index: branches/5.0.x/core/units/users/users_event_handler.php
===================================================================
diff -u -N -r12960 -r12970
--- branches/5.0.x/core/units/users/users_event_handler.php	(.../users_event_handler.php)	(revision 12960)
+++ branches/5.0.x/core/units/users/users_event_handler.php	(.../users_event_handler.php)	(revision 12970)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: users_event_handler.php 12960 2009-12-20 13:11:53Z alex $
+* @version	$Id: users_event_handler.php 12970 2009-12-22 11:02:37Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -255,6 +255,7 @@
 
 					$this->Application->HandleEvent($dummy, 'session-log:OnStartSession');
 					$this->processLoginRedirect($event, $password);
+					$this->_processInterfaceLanguage($event);
 					return true;
 				}
 				else {
@@ -325,6 +326,7 @@
 
 					if (!$remember_login_cookie) {
 						$this->processLoginRedirect($event, $password);
+						$this->_processInterfaceLanguage($event);
 					}
 				}
 				else {
@@ -343,6 +345,47 @@
 		}
 
 		/**
+		 * Sets correct interface language after sucessful login, based on user settings
+		 *
+		 * @param kEvent $event
+		 */
+		function _processInterfaceLanguage(&$event)
+		{
+			if (($event->status != erSUCCESS) || !$this->Application->isAdmin) {
+				return ;
+			}
+
+			$is_root = $this->Application->RecallVar('user_id') == -1;
+
+			$object =& $this->Application->recallObject('u.current');
+			/* @var $object kDBItem */
+
+			$user_language_id = $is_root ? $this->Application->RecallPersistentVar('AdminLanguage') : $object->GetDBField('AdminLanguage');
+
+			$sql = 'SELECT LanguageId, IF(LanguageId = ' . (int)$user_language_id . ', 2, AdminInterfaceLang) AS SortKey
+					FROM ' . TABLE_PREFIX . 'Language
+					WHERE Enabled = 1
+					HAVING SortKey <> 0
+					ORDER BY SortKey DESC';
+			$language_info = $this->Conn->GetRow($sql);
+			$language_id = $language_info && $language_info['LanguageId'] ? $language_info['LanguageId'] : $user_language_id;
+
+			if ($user_language_id != $language_id) {
+				// first admin login OR language was delelted or disabled
+				if ($is_root) {
+					$this->Application->StorePersistentVar('AdminLanguage', $language_id);
+				}
+				else {
+					$object->SetDBField('AdminLanguage', $language_id);
+					$object->Update();
+				}
+			}
+
+			$event->SetRedirectParam('m_lang', $language_id); // data
+			$this->Application->Session->SetField('Language', $language_id); // interface
+		}
+
+		/**
 		 * [HOOK] Auto-Logins Front-End user when "Remember Login" cookie is found
 		 *
 		 * @param kEvent $event