Proxy exception not consistently honoured

[Guest]

I have a very odd problem. There is a site in a partner company that is
accessed via our Intranet, we also have other Intranet sites. The computers
also access the Internet via a proxy.

The IE proxy settings are set via a group policy, so that the proxy is
defined, local sites bypass it, and all the Intranet sites, including the one
of the partner company, are excluded in proxy exceptions.

I have turned Windows Firewall logging on on a PC to see what is going on.

All the Intranet sites work fine other than the partner company's one.

The partner company's site opens fine the first time it is opened in a
particular IE session. If it is refreshed or reloaded, the PC goes to the
proxy, rather than bypassing it, and it doesn't work.

Any ideas what I could try ?

 

[Jon Kennedy]

See these articles for possible help:

Internet Explorer Uses Proxy Server for Local IP Address Even if the "Bypass
Proxy Server for Local Addresses" Option Is Turned On
http://support.microsoft.com/kb/262981/en-us

Intranet site is identified as an Internet site when you use an FQDN or an
IP address
http://support.microsoft.com/kb/303650/en-us