Can you tell me if you had JFBConnect installed before or not? It sounds like JFBConnect is trying to do an upgrade, but the tables that are required are not present on your system.
If this is a new installation or you don't have any old data that you need to keep from a previous JFBConnect installation, I'd recommend uninstalling JFBConnect completely. That would include uninstalling it from the Joomla Install manager and checking to make sure that the /components/com_jfbconnect and /administrator/components/com_jfbconnect directories are deleted.
I hope that helps,
Alex