From ef13f524c1b5c2f5d1f44d730819bf22688ee222 Mon Sep 17 00:00:00 2001
From: Kris Maglione <maglione.k@gmail.com>
Date: Tue, 18 Jan 2011 22:41:41 -0500
Subject: [PATCH] Fix error at shutdown.

---
 common/modules/base.jsm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/common/modules/base.jsm b/common/modules/base.jsm
index 5cdae2b1..2b049555 100644
--- a/common/modules/base.jsm
+++ b/common/modules/base.jsm
@@ -427,7 +427,7 @@ function isinstance(targ, src) {
                 return true;
         }
         else if ("isinstance" in targ) {
-            if (targ.isinstance(src[i]))
+            if (targ.isinstance(src[i]) && targ.isinstance !== isinstance)
                 return true;
         }
         else {