The VPN connection 'xxxxx' failed because there were no valid VPN secretsYou get this message if you have installed openvpn or vpnc in Ubuntu and haven't restarted the network manager. The error is due to GNOME keyring manager cannot find your password in the keyring due to an incomplete configuration. Just restart network manager and you are all set.
hl@braoha:~$ sudo aptitude install network-manager-vpnc
hl@braoha:~$ sudo /etc/init.d/network-manager restart