If I use the default WordPress theme 2012 then it works but it does not if I use my chosen theme Village from http://themeforest.net/item/village-an-awesome-fullscreen-wordpress-theme/237812
The Village theme has it’s own built-in Gallery called Galleries & I am guessing that there might be some conflict here with the plugin name. If I use the 2012 Theme then /?$ is not added to the permalink for the Image Store gallery.