Meridian,
We're really confused about this issue. From every combination of browsers and OS, on your page, we're able to log in with an account and post a message. We only left one message, but the rest, after the pop-up appears it goes away properly and the comment box is ready for our message.
Do you have common virus software, firewalls, or anything else common to the computers or connect you have that could be part of the problem? We really just can't recreate this which makes it tough for us to diagnose.
Another thing to try is on our demo page. I just changed it's setting to allow comments from other providers. Would love to know if you have the same problem there or not:
www.sourcecoast.com/jfbconnect/demo/jfbc-social-modules
Thanks, and keep us posted on what you find,
Alex