When you go to my page with an embedded gallery it loads up that's fine.
For some reason when I click on thumbnails it re-loads the image (I can see this both because you can visually see the image reload, and developer tools shows the script hitting the webserver for the image)
Clicking away from the image to another one, then clicking back to it causes it to load from scratch again.....

It's here: http://lifeshot.cloudvent.net/