Was using your plugin and worked perfectly. I made some changes (upgraded to 3.0.4, changed my site from single install to a multi-site) and now I cannot get the checkbox to show up.
The first successful time around, didn't do anything except configure the settings and add some CSS. This time, I've tried adding the plugin through hooks (I'm on the Pagelines PlatformPro framework) and even inserted
do_action('comment_form',$post->ID); in functions.php to see if that helped. Didn't error, but didn't work either.
Any ideas? my site is located at barroncuadro.com, and you can click into any post.
Thanks for your time!