Plugin's JavaScript fails on admin plugins page

I used this plugin to put a site in maintenance mode before updating from 3.5.2 to 3.6. Everything went perfectly and the site stayed in maintenance mode after the update just like I wanted, until I tried to turn it off. I had to completely deactivate it to do so because the script that expands the settings row did not work. In Firebug, I manually removed the class that hides the settings table row, so I could see the settings, but it would still not let me update the maintenance status to False.

This plugin should really make a submenu item under the main Settings menu and its own page of settings, rather than cram another row into the list of plugins.

http://ww.wp.xz.cn/plugins/wp-maintenance-mode/