Index: branches/unlabeled/unlabeled-1.13.2/core/units/general/main_event_handler.php
===================================================================
diff -u -r5718 -r5905
--- branches/unlabeled/unlabeled-1.13.2/core/units/general/main_event_handler.php	(.../main_event_handler.php)	(revision 5718)
+++ branches/unlabeled/unlabeled-1.13.2/core/units/general/main_event_handler.php	(.../main_event_handler.php)	(revision 5905)
@@ -55,7 +55,7 @@
 
 			$ret = '';
 			$default_language_id = $this->Application->GetDefaultLanguageId();
-			if( $processed_params['m_lang'] != $default_language_id )
+			if( $processed_params['m_lang'] && ($processed_params['m_lang'] != $default_language_id) )
 			{
 				$language_name = $this->Application->getCache('language_names', $processed_params['m_lang']);
 				if ($language_name === false) {
@@ -69,7 +69,7 @@
 			}
 
 			$default_theme_id = $this->Application->GetDefaultThemeId();
-			if( $processed_params['m_theme'] != $default_theme_id )
+			if( $processed_params['m_theme'] && ($processed_params['m_theme'] != $default_theme_id) )
 			{
 				$theme_name = $this->Application->getCache('theme_names', $processed_params['m_theme']);
 				if ($theme_name === false) {
Index: branches/unlabeled/unlabeled-1.13.2/kernel/units/general/main_event_handler.php
===================================================================
diff -u -r5718 -r5905
--- branches/unlabeled/unlabeled-1.13.2/kernel/units/general/main_event_handler.php	(.../main_event_handler.php)	(revision 5718)
+++ branches/unlabeled/unlabeled-1.13.2/kernel/units/general/main_event_handler.php	(.../main_event_handler.php)	(revision 5905)
@@ -55,7 +55,7 @@
 
 			$ret = '';
 			$default_language_id = $this->Application->GetDefaultLanguageId();
-			if( $processed_params['m_lang'] != $default_language_id )
+			if( $processed_params['m_lang'] && ($processed_params['m_lang'] != $default_language_id) )
 			{
 				$language_name = $this->Application->getCache('language_names', $processed_params['m_lang']);
 				if ($language_name === false) {
@@ -69,7 +69,7 @@
 			}
 
 			$default_theme_id = $this->Application->GetDefaultThemeId();
-			if( $processed_params['m_theme'] != $default_theme_id )
+			if( $processed_params['m_theme'] && ($processed_params['m_theme'] != $default_theme_id) )
 			{
 				$theme_name = $this->Application->getCache('theme_names', $processed_params['m_theme']);
 				if ($theme_name === false) {
Index: branches/unlabeled/unlabeled-1.155.2/core/kernel/application.php
===================================================================
diff -u -r5904 -r5905
--- branches/unlabeled/unlabeled-1.155.2/core/kernel/application.php	(.../application.php)	(revision 5904)
+++ branches/unlabeled/unlabeled-1.155.2/core/kernel/application.php	(.../application.php)	(revision 5905)
@@ -1076,13 +1076,20 @@
 			unset($params['__MOD_REWRITE__']);
 		}
 
+		$force_no_sid = false;
+		if( isset($params['__NO_SID__']) )
+		{
+			$force_no_sid = true;
+			unset($params['__NO_SID__']);
+		}
+
 		// append pass through variables to each link to be build
 		$params = array_merge_recursive2($this->getPassThroughVariables($params), $params);
 
 		if ($force_rewrite || ($this->RewriteURLs($ssl) && !$no_rewrite))
 		{
 			$session =& $this->recallObject('Session');
-			if( $session->NeedQueryString() ) $params['sid'] = $this->GetSID();
+			if( $session->NeedQueryString() && !$force_no_sid ) $params['sid'] = $this->GetSID();
 			$url = $this->BuildEnv_NEW($t, $params, $pass, $pass_events);
 			$ret = $this->BaseURL($prefix, $ssl).$url.$map_link;
 		}