Strange behavior using IPTables / Squid / Windows Clients.

Our windows client's arp tables are changing mac addresses for the
firewall starts up a transparent squid server.

Windows client:
Before starting transparent proxy server:
00-07-e9-da-3b-79

A while after starting transparent proxy server:
00-01-02-78-70-ea

The firewall has a public address and private ip address. The problem
is when the arp table changes, the clients then points to the wrong ip
address. All of this is solved when I turn of transparent routing to
the squid server.

--JP