Is that link (with the lang=es) posted during a Like or Comment, or during a some other Facebook event from your site?
Can you look at the page's URL (or post an example) to let us know what the href= tag is for the Like or Comment box or Open Graph tag for that page? These will help us narrow it down. We do create the SEF link for the pages, but it seems like the Joomfish portion isn't modifying the URL properly to re-arrange the languaage parameter.
Thanks for the report, and hopefully, there's an easy solution.
Alzander, here is what I get in my gmail and is the same link posted in facebook:
This is an automated message from JFBConnect.
This is an automated message from JFBConnect.
A new Facebook comment has been posted to: caracas.travel/galipan-venezuela/14004-a...o-en-galipan?lang=es