--- a/util/filters.lua	Wed Jun 02 13:03:55 2010 +0100
+++ b/util/filters.lua	Wed Jun 02 13:31:36 2010 +0100
@@ -19,6 +19,7 @@
 		if filter_list then
 			for i = 1, #filter_list do
 				data = filter_list[i](data);
+				if data == nil then break; end
 			end
 		end
 		return data;