Ahh.. thanks for the explanation.
The likely reason is due to some optimizations that JFBConnect does. In general, we won't tell Facebook to 'parse' the page for it's social widgets unless we know we've put some widgets on the page. It's a performance improvement since it's not requiring unnecessary work. To force the parsing of social widgets, like when you add them yourself, please edit the /components/com_jfbconnect/libraries/provider/facebook.php file. Around line 477, you'll see:
$xfbml = ($this->widgetRendered ? 'true' : 'false');
Add the following right after that:
That will tell JFBConnect to always try to parse tags, whether they are from JFBConnect or not.
In the v6.1 release, due in June, there will be an advanced option to "Always parse social tags" that you'll be able to turn on for just this type of case, instead of having to make a code change.
One thing to note, if you use our social button tags ({JFBCLike} and others), there is extra work we do to try to generate the *best* URL for the current page. That will do things like strip google analytics tags, it understands the URL structure of Joomla, and generally just tries to make sure your Likes are consolidated to one URL instead of multiple URLs to the same content. It's not perfect, but it's (usually) better than just using whatever is in the address bar. That tag can be used anywhere, allowing you to keep your other tags and it all together.
I hope that helps, but if you have any other questions, just let us know.
Thanks,
Alex