Like Gate allows you to reveal some hidden/secret content when the user likes the article. Therefore increasing the likeness of your articles.
Read more in this: http://forum.developers.facebook.net/viewtopic.php?id=93201
Please, use the iframe solutions if possible for now. It seems when the hidden code contains script tag the script code doesn't get evaluated/executed.
When you disable the plugin (that's within the plugin but the plugin is activate in WordPress) all the short codes will be removed (visually) but not from the database. It is recommended to disable the plugin and not deactivate/uninstall it when you don't need it anymore. That way you won't see any unreplaced short tags in your posts.
Support is handled on our site: http://club.orbisius.com/forums/forum/community-support-forum/wordpress-plugins/like-gate/ Please do NOT use the WordPress forums or other places to seek support.