Win2k domain can’t browse own website

I have a Windows SBS (windows 2000) and I am using
ISA. The server is multihomed and has a public ip
address on one NIC. My domain is the same as my
website, and my website is hosted external to my
network. I can access any website I want, but when I go
to my website, it states “destination host unreachable”.
I have created a host record in DNS to point to the real
website.. and the only thing that helped was now the
server can browse there… the clients still cannot. Our
domain is company.com and the website is
www.company.com. We are using DHCP, DNS, ISA on
our server. I have tried a hosts file on the client as well
as the server and I have tried flushing dns.