--- a/mod_log_auth/mod_log_auth.lua	Sun Jun 30 01:12:24 2013 +0200
+++ b/mod_log_auth/mod_log_auth.lua	Sun Jun 30 01:13:49 2013 +0200
@@ -1,4 +1,4 @@
 
 module:hook("authentication-failure", function (event)
-	module:log("info", "Failed authentication attempt (%s) from IP: %s", event.condition, event.session.ip);
+	module:log("info", "Failed authentication attempt (%s) from IP: %s", event.condition or "unknown-condition", event.session.ip or "?");
 end);