I saw that this issue has been reported a couple of times on the website, but no solution has been offered. Let's get this settled once and for all, shall we? :)
The facebook plugin works great, to the extenct that it registers a new user with the full name of the logged in facebook user as the username and its e-mail as the username e-mail, but that's about it.
On the Q2A website, the plugin pulls the avatar and fills the name, website and location fields automatically. This is not the case in my instance. Am I missing some PHP modules or the likes? I can happily provide a screen if necessary.
If anyone else encountered this and managed to solve it, please share the solution. Like I said, there are a lot of people who have and are still experiencing this important problem. Thank you in advance for your replies!