Index: branches/5.1.x/core/kernel/application.php
===================================================================
diff -u -N -r14326 -r14348
--- branches/5.1.x/core/kernel/application.php	(.../application.php)	(revision 14326)
+++ branches/5.1.x/core/kernel/application.php	(.../application.php)	(revision 14348)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: application.php 14326 2011-05-20 08:13:02Z alex $
+* @version	$Id: application.php 14348 2011-05-23 08:02:12Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -1135,7 +1135,8 @@
 
 		if ($this->UseOutputCompression()) {
 			$compression_level = $this->ConfigValue('OutputCompressionLevel');
-			if ($compression_level < 0 || $compression_level > 9) {
+
+			if (!$compression_level || $compression_level < 0 || $compression_level > 9) {
 				$compression_level = 7;
 			}
 
@@ -2394,6 +2395,8 @@
 			return $res['VariableValue'];
 		}
 
+		trigger_error('Usage of undefined configuration variable "<strong>' . $name . '</strong>"', E_USER_NOTICE);
+
 		return false;
 	}
 
@@ -2825,12 +2828,12 @@
 
 			$args = '';
 			$type = isset($trace_info['type']) ? $trace_info['type'] : '';
-			
+
 			if ( isset($trace_info['args']) ) {
 				foreach ($trace_info['args'] as $argument) {
 					if ( is_object($argument) ) {
 						$args .= get_class($argument) . ' instance, ';
-					} 
+					}
 					else {
 						$args .= is_array($argument) ? 'Array' : substr($argument, 0, 10) . ' ..., ';
 					}
Index: branches/5.1.x/core/units/helpers/modules_helper.php
===================================================================
diff -u -N -r14241 -r14348
--- branches/5.1.x/core/units/helpers/modules_helper.php	(.../modules_helper.php)	(revision 14241)
+++ branches/5.1.x/core/units/helpers/modules_helper.php	(.../modules_helper.php)	(revision 14348)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: modules_helper.php 14241 2011-03-16 20:24:35Z alex $
+* @version	$Id: modules_helper.php 14348 2011-05-23 08:02:12Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -247,8 +247,7 @@
 		 */
 		function _GetDomain($vars)
 		{
-			$config_domain = array_key_exists('Domain', $vars) ? $vars['Domain'] : false;
-			return $this->Application->ConfigValue('DomainDetect') ? $_SERVER['HTTP_HOST'] : $config_domain;
+			return isset($vars['Domain']) ? $vars['Domain'] : false;
 		}
 
 		function _keyED($txt, $encrypt_key)