Safari 4.0.4 on OSX Snow Leopard. No problem here. I have often had similar problems when using Firefox on Caedes. When clicking the small image the new window opens with the same page and not the full size image. Restarting Firefox seems to fix it every time.
I checked and it says it is says to accept cookies "only from sites I visit". Anyway it's obviously a user issue and not a site issue like I thought it might be.
Using the latest version of Safari on OSX Leopard.