It's working fine for me in IE. In Chrome, I'm getting a redirect loop. This is likely due to disabling some of the JFBConnect plugins, but still having something that loading JFBConnect in general.
To disable from your system, try the following ordering of things. It really shouldn't matter, but obviously, something's not right:
1) In JFBConnect configuration, turn off "Automatically Log Facebook Users In", if it's enabled.
2) Unpublish any JFBC modules
3) Then, disable the content, user, authentication, and system plugins from JFBConnect.
The redirect loop is likely because you're logged into Facebook in one tab, but have disabled some of the plugins from JFBConnect.. so the autologin isn't working properly without the plugins. To fix, try closing your browser entirely and revisiting the site without logging into Facebook. This shouldn't effect the admin area at all though, as we try to not load much/anything Facebook related when in that section.
Hope this helps,
Alex