python – 避免OpenERP audittrail错误

我想通过安装audittrail模块来管理OpenERP用户的活动.
创建一些规则(定义哪个用户,哪个对象以及将监视哪个活动(创建,更新…)).我更新了一个产品,看它是否有效.
当我尝试更新产品时,我遇到了系统错误.看到日志,我明白了
[2010-08-31 12：53：35,042]光标未明确关闭
[2010-08-31 12：53：35,043]光标创建于/home/pilgrim/working/sources/addons/audittrail/audittrail.py:204
这里导致错误的行
??????????cr = pooler.get_db(db).cursor()
看一下sql_db.py,我收到了评论

def __del__(self):
    if not self.__closed:
        # Oops. 'self' has not been closed explicitly.
        # The cursor will be deleted by the garbage collector,# but the database connection is not put back into the connection
        # pool,preventing some operation on the database like dropping it.
        # This can also lead to a server overload.
        msg = "Cursor not closed explicitlyn"  
              "Cursor was created at %s:%s" % self.__caller
        log(msg,netsvc.LOG_WARNING)
        self.close()

由于我是Python的新手,我不知道如何克服这个问题？
任何提示都可以克服这个问题？
谢谢

cr = sqldb.db_connect(dbname).cursor()
.........
cr.close()
cr = None