My ISP Proxy and ipchains

[Antti Tolamo <antti@tola.org>]

Hello,

I have Debian 2.2 potato that works as
a server for my small Windows homenetwork.

I use with potato ipchains to do IP masquerade and
a firewall. I have ADSL connection to net.

My problem is this:

My ISP proxy works well - except if I connect
to it through masquerading from local network.
Then webmail forms and similar don't work anymore.
I can't for example send mail.

Otherwise through Squid or directley from Linux
everything works like it should. Fixing firewall
rules does not make any diffrence.

Is this normal ipchains masquerade behaviour
or I'm missing something?

Regards,

ANtti