I am on the Intranet
Perish the thought that you would be using IGS for this?
Check your proxy settings in IE to see that r.mil.uk is on the list for "do not use proxy server for...". If that doesn't help call the contradiction in terms that is your local IT helpdesk.
(favourite quote from our place - "I'd like more RAM please" "Oh, have you got a message to say your hard disk quota is full?")