Pier,
Looking into it to test.. but want to make sure of some things. In your Facebook Application, the "Page Tab URL" (and Secure Page Tab URL) are set to:
www.play-guitar.sg/index.php?option=com_...d=129&tmpl=component
Correct?
When I go to the FB Page (without Liking it), I'm actually getting a page timeout error. Even when I Like the FB Page, I get the same error. Are you seeing it at all? If not, I'm not sure if it's a JFBConnect or Joomla configuration issue that's causing a redirection loop (or something similar). If you can see the error, please try turning off any gzipping (in the global config of Joomla or any minimization plugins you may have) and turn Error Reporting to 'maximum'. If there's a PHP error, that can cause the non-loading error I'm seeing, but we'd need to know the error to diagnose the problem.
This webpage is not available
Google Chrome could not load the webpage because www.play-guitar.sg took too long to respond. The website may be down, or you may be experiencing issues with your Internet connection.
Hope that helps get started, but obviously, somethings wrong (even though we're both seeing different 'wrong' things).
Thanks,
Alex