error in cvstreedefault

[amyxo]

keep getting the following errors :
Error: $cvstreedefault points to a repository not defined in %CVSROOT
(edit your configuration file /usr/local/apache/conf/cvsweb.conf) 

in cvsweb.conf :
%CVSROOT = (
               'Development' => '/cvs',
               'Configuration' => '/cvs/CVSROOT/config',
               'HTML-files' => '/usr/local/apache/htdocs'
            );
$cvstreedefault = 'Configuration';


what did I do wrong ?  any idea ?
Thank you.