--- a/server/session.py	Wed Apr 02 12:38:02 2014 +0200
+++ b/server/session.py	Thu Apr 03 18:09:57 2014 +0200
@@ -1654,7 +1654,8 @@
         with self._lock:
             self._closed = True
         tracker.close()
-        self._rollback()
+        if self._cnx._session_handled:
+            self._rollback()
         self.debug('waiting for open connection of session: %s', self)
         timeout = 10
         pendings = tracker.wait(timeout)