Index: pokernetwork/pokersite.py
===================================================================
--- pokernetwork/pokersite.py	(revision 6351)
+++ pokernetwork/pokersite.py	(working copy)
@@ -154,6 +154,8 @@
         self.expired = True
     
     def checkExpired(self):
+        if self.expired:
+            return False
         try:
             #
             # The session may expire as a side effect of the
Index: tests/test-pokersite.py.in
===================================================================
--- tests/test-pokersite.py.in	(revision 6351)
+++ tests/test-pokersite.py.in	(working copy)
@@ -710,6 +710,16 @@
             session.expire()
             self.assertEqual(True, session.expired)
 
+      def test02_expireFromTwisted(self):
+            uid = 'uid'
+            auth = 'auth'
+            session = self.site.makeSessionFromUidAuth(uid, auth, 'yes')
+            self.site.memcache.set(uid, '0')
+            self.site.memcache.set(auth, '0')
+            session.lastModified = 0
+            session.expire()
+            session.checkExpired()
+
 class RequestTestCase(PokerSiteBase):
 
       def test01_name(self):