I first installed it in a directory named "cms". I created my website, very nice, but now I would want to change the directory name of the installation, from "cms", to "fr".
So I empty the cache in "global parameters", then change the name of the directory, then change the config.php lines Path settings in order to point to the right directories.
However, this does not work : instead, I have the following errors

Warning: require_once(/home/www/vhosts/le-valombre.fr/httpdocs/cms/fileloc.php) [function.require-once]: failed to open stream: No such file or directory in /home/www/vhosts/le-valombre.fr/httpdocs/cms/index.php on line 23
Fatal error: require_once() [function.require]: Failed opening required '/home/www/vhosts/le-valombre.fr/httpdocs/cms/fileloc.php' (include_path='.:.:/usr/share/php') in /home/www/vhosts/le-valombre.fr/httpdocs/cms/index.php on line 23
It seems it is still searching for a cms directory , but I changed all the directories in the config.php in the Path Settings part ! What's happening ? It should be possible to change the root directory or what ?