--- trunk/lib/WebPAC/Output/Estraier.pm	2005/11/23 00:14:00	112
+++ trunk/lib/WebPAC/Output/Estraier.pm	2005/11/23 00:14:05	113
@@ -146,7 +146,7 @@
 
 	# filter all tags which have type defined
 	my @tags = grep {
-		defined( $args->{'ds'}->{$_}->{$type} )
+		ref($args->{'ds'}->{$_}) eq 'HASH' && defined( $args->{'ds'}->{$_}->{$type} )
 	} keys %{ $args->{'ds'} };
 
 	$log->debug("tags = ", join(",", @tags));