Triangle,
You're trying to install the Joomla 1.5 version into a Joomla 1.6+ site. You should use the com_jfbconnect_j2.5_xxxx files only. The Joomla 1.5 ones won't work.
Hope that's all it is, but if you run into anything else, let us know!
I'd highly recommend upgrading from 1.7x. to 2.5. There are some big security vulnerabilities in 1.7 (and even early 2.5 releases). 1.7 is also no longer supported by Joomla.org.
Good luck,
Alex