--- class.tslib_menu.php-orig	2007-03-27 12:27:34.000000000 +0200
+++ class.tslib_menu.php	2007-03-27 12:28:17.000000000 +0200
@@ -1249,7 +1249,7 @@ class tslib_menu {
 		$cls = strtolower($this->conf[($this->menuNumber+1).$objSuffix]);
 		$subLevelClass = ($cls && t3lib_div::inList($this->tmpl->menuclasses,$cls)) ? $cls : '';
 
-		if ($subLevelClass && ($this->mconf['expAll'] || $this->isNext($uid, $this->getMPvar($this->I['key'])) || is_array($altArray)) && !$this->mconf['sectionIndex'])	{
+		if (is_array($altArray) && $subLevelClass && ($this->mconf['expAll'] || $this->isNext($uid, $this->getMPvar($this->I['key'])) || is_array($altArray)) && !$this->mconf['sectionIndex'])	{
 			$submenu = t3lib_div::makeInstance('tslib_'.$subLevelClass);
 			$submenu->entryLevel = $this->entryLevel+1;
 			$submenu->rL_uidRegister = $this->rL_uidRegister;