Sergio,
You look to have another Facebook extension installed on your site and that is likely causing the problem. The Autotune Error Checker should have noted this as well. Basically, if you open the HTML of your home page, you can see the all.js file (the Facebook Javascript library) being loaded twice as well as Open Graph tags being included twice. You'll need to disalbe or remove the other extension to ensure that JFBConnect works properly.
If you disable the other extension and still run into issues, just let us know!
Thanks,
Alex