Thanks for testing the page gang, the image server is now taking care of all pictures on both Sims sites, which helps a lot. I have enough stuff on the network the server needs to send about 60 items (images, styling, javascript) every second during peak hours and taking pictures out made it easier to handle high loads, which we need for the days after Christmas when we see a lot more people coming around.
The 403 was what I wanted, as it would have just told you the site wasn't found if your area did not have it. I found a newer tool that tells you how far a new domain has spread, so am able to see 90% of the world will get pictures so switched it over.