Image Gallery not loading random thumbnails
I just checked out your site and all images showed up. It took some time, but all images did show up. Looking at it further, it appears that you have your file system set to private. Go to admin/settings/file-system/settings and change the Download method to public. If this is not an option, then I would look at implementing xsend in apache and installing the drupal module http://drupal.org/project/xsend

Unless you have some VERY good reasons to set your file system to private, I highly recommend using a public file system.