Cant be the hosts file. Theres nothing in there, so the resolver on my machine will head straight off to the DNS if required. Besides, the image is coming from the same host as that serving up the HTML.
Tried the cache thang just out of curiosity, but made no difference.
No common theme in browser. Some people have it working in the same as others have it failing. Might just be a fuck up on the webserver itself. They're not infalible!
Gonna try it with wget when I get back into work tomorrow. Determined to find out the cause