First, let's get the button to show up, then we can deal with it not working properly.
* Please make sure caching is disabled on your site and our JFBCSystem plugin is enabled.
* When I go to your page and click on the sidebar "my account" item, it brings me to the Joomla users component. Can you enable the JFBConnect > Configuration > General > 'Integrate into Joomla Login' setting? Unless you've done a template override, this should make the button appear.
* If there's another way to log in on your page, such as via the SCLogin module, please let me know instructions on how to do this.
-Melissa