Background also not displaying (with custom page template)

I’m using a child theme of TwentyEleven, with a custom page template called Fullwidth. I’m attempting to use this plugin to remove the content background image and just display a white background in the page content area. I actually can’t get the backgrounds to display with any page template, and changing the Settings>Reading options>Blog Page doesn’t fix that. (I’d actually prefer to set the background for the template, but thought I’d try this plugin since I haven’t been able to figure out how to do that.) Any clues? Thanks!!!
Site: http://bit.ly/X0zSli
WP 3.5.1

http://wordpress.org/extend/plugins/background-per-page/