[Twisted-web] mysql connect raise error although reconnect=true

hello i have an xmlrpc daemon running and uses mysql for authorization. I noticed that the connection will timeout after a period of time. After investigated in the api, i found the cp_reconnect switch adbapi.ConnectionPool(DB_DRIVER,cp_reconnect=True, **DB_ARGS) however, my problem is, although the deamon will reconnect to mysql, it did raise an error and turn down the first login attempt before automatically reconnect the timeouted connection I wonder if this is normal and this switch is intented to raise error before reconnect? thanks Andrey k.