Display problems with certain websites II

Vista appears to be having a problem with my network. Some websites
show up without properly loading stylesheets and/or images. It
appears that perhaps it occurs when the resource is on a different
server from the main page.

The most obvious web page with this problem is microsoft.com!
http://www.microsoft.com/en/us/default.aspx

Another page that often fails: http://nytimes.com

Here's what it looks like in IE 7 and in Safari on Vista:
http://research.pdmagic.com/test/vistaIE7/microsoft_com.pdf


Here you can see that .js and .css are loaded from different machine
names:
<script type="text/javascript"
src="http://i3.microsoft.com/shared/core/1/js/library.js">

@import url('http://i2.microsoft.com/shared/core/1/css/core.css');

The problem is specific to Vista, and appears to be specific to my
network. Here are the facts:

1. I installed Vista 32 Ultimate on my Laptop in January and
experienced the problem, so uninstalled.
2. Recently installed Vista 64 Ultimate on my desktop and have the
same problem.
3. Recently installed Vista 32 Ultimate on my laptop (again) - same
problem.
4. There are about 6 computers in the office running XP, 2K, 2003
that do not have this problem. (running a variety of browsers
including IE7)
5. I put a VMWare virtual machine on the Vista 64 desktop - XP pro in
the VM. It doesn't have the problem.
6. I put the same VMWare XP Pro virtual machine on the laptop running
Vista 32. Also doesn't have the problem.
7. Went to a different network and problem goes away completely.
8. Problem occurs on my network using wireless OR wired NIC's.
9. Other computers that work in the office are connected to same
switch as the two that don't work.
10. The problem in intermittent. It works 10% of the time, fails 90%
of the time.

My network configuration is:
DSL from Qwest
Cisco 678 DSL Modem/Router
GnatBox firewall software running on computer with Intel GB NIC's
Netgear GB switch

I'd like to install Vista on other systems in the office, but can't
afford to have them fail on common web sites.

Suggestions?

Thanks,

-Pete

The "II" in the subject refers to this post by someone else:

From: =?Utf-8?B?S0M=?= <KC.RemoveThis@discussions.microsoft.com>
Subject: Display Problems on Certain Websites
Date: Tue, 26 Jun 2007 21:18:00 -0700
Message-ID: <2F80B22E-36D2-4211-A2E7-C147B9F26DFF.RemoveThis@microsoft.com>

Our problems seem similar.

-Pete