Index: class.t3lib_pagerenderer.php
--- class.t3lib_pagerenderer.php Base (BASE)
+++ class.t3lib_pagerenderer.php Locally Modified (Based On LOCAL)
@@ -1178,6 +1178,7 @@
 			$localeMap['no'] = 'no_BO'; // Norwegian Bokmaal
 			$localeMap['se'] = 'se_SV'; // Swedish
 
+			$this->lang = $GLOBALS['LANG']->lang;
\ No newline at end of file
 
 			$extJsLang = isset($localeMap[$this->lang]) ? $localeMap[$this->lang] : $this->lang;
 				// TODO autoconvert file from UTF8 to current BE charset if necessary!!!!