Index: branches/5.2.x/core/install.php
===================================================================
diff -u -N -r15000 -r15012
--- branches/5.2.x/core/install.php	(.../install.php)	(revision 15000)
+++ branches/5.2.x/core/install.php	(.../install.php)	(revision 15012)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: install.php 15000 2012-01-06 16:31:48Z alex $
+* @version	$Id: install.php 15012 2012-01-06 20:38:49Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -387,6 +387,13 @@
 					break;
 
 				case 'install_setup':
+					if ( $this->Application->TableFound(TABLE_PREFIX . 'UserSession', true) ) {
+						// update to 5.2.0 -> rename session table before using it
+						// don't rename any other table here, since their names could be used in upgrade script
+						$this->Conn->Query('RENAME TABLE ' . TABLE_PREFIX . 'UserSession TO ' . TABLE_PREFIX . 'UserSessions');
+						$this->Conn->Query('RENAME TABLE ' . TABLE_PREFIX . 'SessionData TO ' . TABLE_PREFIX . 'UserSessionData');
+					}
+
 					$next_preset = $this->Application->GetVar('next_preset');
 					if ($next_preset !== false) {
 						$user_helper =& $this->Application->recallObject('UserHelper');
@@ -651,7 +658,7 @@
 							'l1_Description' => 'Content', 'Status' => 4,
 						);
 
-						$this->Conn->doInsert($fields_hash, $this->toolkit->getSystemConfig('Database', 'TablePrefix') . 'Category');
+						$this->Conn->doInsert($fields_hash, $this->toolkit->getSystemConfig('Database', 'TablePrefix') . 'Categories');
 
 						$this->toolkit->SetModuleRootCategory('Core', $this->Conn->getInsertID());
 
@@ -1042,7 +1049,7 @@
 							'VariableName'	=>	'InstallFinished',
 							'VariableValue'	=>	1,
 						);
-						$this->Conn->doInsert($fields_hash, TABLE_PREFIX.'ConfigurationValues');
+						$this->Conn->doInsert($fields_hash, TABLE_PREFIX.'SystemSettings');
 					}
 					break;
 			}
@@ -1343,12 +1350,13 @@
 		function AlreadyInstalled()
 		{
 			$table_prefix = $this->toolkit->getSystemConfig('Database', 'TablePrefix');
+			$settings_table = $this->TableExists('ConfigurationValues') ? 'ConfigurationValues' : 'SystemSettings';
 
 			$sql = 'SELECT VariableValue
-					FROM ' . $table_prefix . 'ConfigurationValues
+					FROM ' . $table_prefix . $settings_table . '
 					WHERE VariableName = "InstallFinished"';
 
-			return $this->TableExists('ConfigurationValues') && $this->Conn->GetOne($sql);
+			return $this->TableExists($settings_table) && $this->Conn->GetOne($sql);
 		}
 
 		function CheckDatabase($check_installed = true)