I'm using your plugin on a tech-savvy site, so I an many of my users have Facebook's "secure browsing" https option enabled in our Facebook accounts. So long as this is enabled, my FB user icon does not populate into the comment box, and trying to leave a comment prompts me to log in to Facebook via the popup window (even though I'm already logged in). When I re-enter my login info in the popup, it finishes with a blank window and I'm still unable to leave a comment.
When I turn off https secure browsing in my FB account settings, the plugin functions normally on my site.
Any thoughts? Thank you for all the hard work.