Mike
The "scuttlebutt" from the hacker illuminati is that proxy server 2 alone is not enough, you need to combine it with a hardware firewall. Take a look at securityspace.com from behind your proxy server and take the basic test, i did and got a hell of a fright...
Regards
JR
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1