Exception type SSL.Error

Exception Handler Information
Traceback (most recent call last):
File "/usr/bin/../share/rhn/rhn_applet/rhn_applet.py", line 448, in refresh
self.model.refresh(force)
File "/usr/bin/../share/rhn/rhn_applet/rhn_applet_model.py", line 264, in refresh
self.__rpc_server__.refresh(force)
File "/usr/bin/../share/rhn/rhn_applet/rhn_applet_rpc.py", line 84, in refresh
status = server.applet.poll_status()
File "/usr/lib/python2.2/xmlrpclib.py", line 821, in __call__
return self.__send(self.__name, args)
File "/usr/lib/python2.2/site-packages/rhn/rpclib.py", line 126, in _request
verbose=self._verbose
File "/usr/lib/python2.2/site-packages/rhn/transports.py", line 130, in request
headers, fd = req.send_http(host, handler)
File "/usr/lib/python2.2/site-packages/rhn/transports.py", line 614, in send_http
headers=self.headers)
File "/usr/lib/python2.2/httplib.py", line 701, in request
self._send_request(method, url, body, headers)
File "/usr/lib/python2.2/httplib.py", line 723, in _send_request
self.endheaders()
File "/usr/lib/python2.2/httplib.py", line 695, in endheaders
self._send_output()
File "/usr/lib/python2.2/httplib.py", line 581, in _send_output
self.send(msg)
File "/usr/lib/python2.2/httplib.py", line 560, in send
self.sock.sendall(str)
File "/usr/lib/python2.2/site-packages/rhn/SSL.py", line 191, in write
sent = self._connection.send(data)
Error: [('SSL routines', 'SSL3_GET_SERVER_CERTIFICATE', 'certificate verify failed')]
This is what happens when I try to use the RHN updating , How can I fix it? every time i try to do it again, it gives the same error.