--- /usr/lib/python2.7/threading.py.orig	2012-03-14 18:27:12.718700850 -0500
+++ /usr/lib/python2.7/threading.py	2012-03-14 18:28:03.452508619 -0500
@@ -806,7 +806,8 @@ class _DummyThread(Thread):
         # Thread.__block consumes an OS-level locking primitive, which
         # can never be used by a _DummyThread.  Since a _DummyThread
         # instance is immortal, that's bad, so release this resource.
-        del self._Thread__block
+        if hasattr(self, '_Thread__block'):
+            del self._Thread__block
 
         self._Thread__started.set()
         self._set_ident()