WPG2 URL's 404.

I have a site set up at http://www.backpackingadventure.net

The plugin works great for me, if I am logged into the site as administrator. The links in the post and side bar pull up the correct image. When I am not logged in then 404. I have done a bunch of searching, i've also reinstalled all this a few times just to make sure. But I keep ending up here

anyone have any advice ?