As for your problem, lets start with the stupid stuff first. This will also
help other members of this list to help you track down the problem.
1. What is the URL of the site that's crapping out?
2. Are you doing your own primary DNS?
2b. If you are, have your hosts be registered with InterNIC and are they
responding correctly to nslookups?
3. IIS specific - do you have a document correctly named to be the default?
Typically, this would by default.htm, default.html, index.htm or
index.html...or many others. You can check this in the settings of IIS for
that web server.
It almost sounds like internally there is no default page specified and
directory browsing is disabled so it's just churning around trying to find
something it can't and eventually just pukes on ya.