issues with a slider – investigations with firebug

The .js file for the carousel is not loading, I get a 404 instead:

GET http://www.ex-libri.org/wp-content/plugins/jquery.jcarousel.min.js?ver=1.0 [HTTP/1.1 404 Not Found 98ms]

It looks like either there is a plugin’s subfolder missing in the path or the path of plugins folder has been used instead of the theme path.