For what I see the Facebook like button works on lightbox effect on your site.
Shutting down when you click back in the browser is exactly how the browser works, and has nothing to do with the plugin (this or any other). You just go to previously opened page.
How to Get Support
After you register and login to the site, you may post all plugin support questions in the Support Forum.
If you need to provide private info, please create a ticket and then reply to it using Set as private reply option.