Steve,
Sorry to hear that wasn't the issue. On your page now, I'm seeing 2 comment boxes - The top from JFBConnect saying that "an href parameter is required' and the lower is your addition. However, the new comment box is causing other problems that will make it hard to debug. Can you remove the script inclusion in the code you added? Mainly, don't include Facebook's all.js file. JFBConnect should be doing that already, and doing it twice is bad.
I also just noticed you're using JFBConnect 3.2.1. Version 3.2.2 fixed a minor bug with the {JFBCComments} tag which can cause that "href parameter is required" error by always setting the href parameter.. before, it was ok not to do that, but in May, FB changed that policy, and we updated accordingly. If you'd prefer not to upgrade, can you try adding the href to your {JFBCComments href=http://linktosite.com/} tag?
Additionally, JFBConnect 3.4 was just released (yesterday) which has a lot more features and other improvements. It's possible that simply upgrading (just use the Joomla installer like normal) will fix the remaining issue you're seeing. If not, let us know when that script tag is removed and you've upgraded or changed the tag, and we'll start again from there.
For more information on the recent changes to JFBConnect, see:
www.sourcecoast.com/jfbconnect/docs/changelog
Thanks,
Alex