You posted in the JFBConnect 1.5 forums. Are you still using Joomla 1.5? If so, please ensure you downloaded the Joomla 1.5 version, which is JFBConnect v4.3.0
If you're using Joomla 2.5 or 3.0, similarly, make sure you downloaded the correct version of those, but they should perform a check when installing to ensure they are on the right version.
Finally, I'd try re-installing the main com_jfbconnect_vxy_jxy.zip file again. That should attempt to copy all the necessary files over again. In the installer, make sure there are no error messages that appear.
Let me know if any of the above helps get you going. I'm not sure what the problem would be as that's not something we've heard of, but we'll gladly help investigate.
Thanks,
Alex