[Plugin: WP Supersized] "Another" doesn't work

This is what differs on the second tab

Select the page template(s) where Supersized should be used:

Sorry, no template found. Your theme is not using any non-standard page template

What does that mean?

The plugin gets the list of templates by calling the standard WP function get_page_templates(). I have no experience with Artisteer but it would look like the template generated by Artisteer is not compliant with the WP standards ?
Make sure that your template contains its name in the correct way, like this:

<?php
/*
Template Name: name of you template
*/
?>

Have a look here for examples of page templates.