I'm in the process of creating a Facebook app that uses a Page Tab. However, when I access a page where the app is installed a
signed_request parameter is not sent to my script. Neither
$_REQUEST are being sent any data (and using the Facebook PHP SDK
$facebook->getSignedRequest() also does not work)
It turned out to be a stupid oversight on my end, I had typed
http://example.com which redirected to
http://www.example.com the redirected page didn't have data posted to it.