Index: pool.py
===================================================================
--- pool.py	(revision 4336)
+++ pool.py	(working copy)
@@ -55,6 +55,8 @@
     critical times because of a timeout on the Connection.
     """
     try:
+        if hasattr(cnx, 'ping'):
+            cnx.ping()
         cnx.rollback() # resets the connection
         return True
     except Exception: