--- a/xmpp/roster.go	Sun Sep 08 14:37:56 2013 -0700
+++ b/xmpp/roster.go	Sun Sep 08 14:40:35 2013 -0700
@@ -59,6 +59,9 @@
 				f()
 			}
 			iq, ok := stan.(*Iq)
+			if !ok {
+				continue
+			}
 			if iq.Type != "set" {
 				continue
 			}