Index: branches/5.0.x/core/kernel/utility/unit_config_reader.php
===================================================================
diff -u -r12167 -r12195
--- branches/5.0.x/core/kernel/utility/unit_config_reader.php	(.../unit_config_reader.php)	(revision 12167)
+++ branches/5.0.x/core/kernel/utility/unit_config_reader.php	(.../unit_config_reader.php)	(revision 12195)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: unit_config_reader.php 12167 2009-08-04 16:21:38Z alex $
+* @version	$Id: unit_config_reader.php 12195 2009-08-05 09:56:28Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -724,8 +724,18 @@
 					$config['AdminTemplatePath'] = $module_templates . $config['AdminTemplatePath'];
 				}
 
+				if (array_key_exists($prefix, $this->prefixFiles) && ($this->prefixFiles[$prefix] != $filename)) {
+					trigger_error(
+						'Single unit config prefix "<strong>' . $prefix . '</strong>" ' .
+						'is used in multiple unit config files: ' .
+						'"<strong>' . $this->prefixFiles[$prefix] . '</strong>", "<strong>' . $filename . '</strong>"',
+						E_USER_WARNING
+					);
+				}
+
 				$this->configData[$prefix] = $config;
 				$this->prefixFiles[$prefix] = $filename;
+
 				return $prefix;
 			}
 			elseif ($prefix = array_search($filename, $this->prefixFiles)) {
Index: branches/5.0.x/core/units/general/helpers/sections_helper.php
===================================================================
diff -u -r12117 -r12195
--- branches/5.0.x/core/units/general/helpers/sections_helper.php	(.../sections_helper.php)	(revision 12117)
+++ branches/5.0.x/core/units/general/helpers/sections_helper.php	(.../sections_helper.php)	(revision 12195)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: sections_helper.php 11892 2009-07-01 08:35:06Z alex $
+* @version	$Id: sections_helper.php 12195 2009-08-05 09:56:28Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -58,7 +58,7 @@
 				$this->Application->UnitConfigReader->ReReadConfigs();
 			}
 
-			$this->Tree = Array();
+			$this->Tree = Array ();
 
 			// 1. build base tree (don't update parent with children list yet)
 
@@ -110,6 +110,11 @@
 				$parent_section = $section_params['parent'];
 				$section_order = "{$section_params['priority']}";
 
+				if (!isset($parent_section)) {
+					// don't process parent section of "in-portal:root" section
+					continue;
+				}
+
 				if (!array_key_exists('children', $this->Tree[$parent_section])) {
 					$this->Tree[$parent_section]['children'] = Array ();
 				}