Profile picture isn't displayed

Hi,
I finally downloaded the free version, and have an issue on it.

Indeed, comments imported do not have any profile picture (they have an identicon, which is actually the same for all Facebook posters).
You can see that on the screens below :

Facebook comment : http://nsa33.casimages.com/img/2014/09/28/140928073737847798.jpg
Wordpress imported comment (public) : http://nsa33.casimages.com/img/2014/09/28/140928073737900419.jpg
Wordpress imported comment (wp-admin) : http://nsa34.casimages.com/img/2014/09/28/140928073738132698.jpg (btw, as you can see, the link attached to this comment is not the facebook’s author page but the facebook home page… Is it normal ?)

Thanks in advance for your help 🙂
Maël.

https://wordpress.org/plugins/fb-comments-importer/