Index: wordpress/wp-includes/theme.php
===================================================================
--- wordpress/wp-includes/theme.php	(revision 13211)
+++ wordpress/wp-includes/theme.php	(working copy)
@@ -624,7 +624,7 @@
 	if ($stylesheet_or_template) {
 		$theme_roots = get_theme_roots();
 
-		if ( $theme_roots[$stylesheet_or_template] )
+		if ( isset( $theme_roots[$stylesheet_or_template] ) && $theme_roots[$stylesheet_or_template] )
 			$theme_root = WP_CONTENT_DIR . $theme_roots[$stylesheet_or_template];
 		else
 			$theme_root = WP_CONTENT_DIR . '/themes';
Index: wordpress/wp-settings.php
===================================================================
--- wordpress/wp-settings.php	(revision 13211)
+++ wordpress/wp-settings.php	(working copy)
@@ -39,6 +39,13 @@
 
 // Standardize $_SERVER variables across setups.
 wp_fix_server_vars();
+	
+/**
+ * global $_SERVER array initialisation if certain indexes are not used
+ */	
+foreach ( array( 'HTTP_HOST', 'REQUEST_URI', 'SERVER_SOFTWARE' ) as $var )
+	if ( !isset($_SERVER[$var]) )
+		$_SERVER[$var] = '';
 
 // Check for the required PHP version and for the MySQL extension or a database drop-in.
 wp_check_php_mysql_versions();