Index: t3lib/class.t3lib_div.php
===================================================================
--- t3lib/class.t3lib_div.php	(revision 7509)
+++ t3lib/class.t3lib_div.php	(working copy)
@@ -2026,10 +2026,8 @@
 	 */
 	public static function array_merge_recursive_overrule(array $arr0,array $arr1,$notAddKeys=0,$includeEmtpyValues=true) {
 		foreach ($arr1 as $key => $val) {
-			if(is_array($arr0[$key])) {
-				if (is_array($arr1[$key]))	{
-					$arr0[$key] = self::array_merge_recursive_overrule($arr0[$key],$arr1[$key],$notAddKeys,$includeEmtpyValues);
-				}
+			if (isset($arr0[$key]) && is_array($arr0[$key]) && is_array($arr1[$key])) {
+				$arr0[$key] = self::array_merge_recursive_overrule($arr0[$key],$arr1[$key],$notAddKeys,$includeEmtpyValues);
 			} else {
 				if ($notAddKeys) {
 					if (isset($arr0[$key])) {