error after upgrade to 2

Hello

i just made the upgrade. everything's been fine and piwik is up and working, but all my personnal scripts are not working any more. i have this kind of message:

Quote
Fatal error: Class 'FrontController' not found in /home/www/xxx.com/htdocs/doPiwikLogin.php on line 27

i've double checked path and files, and everything is fine...any help would be appreciated

using PHP Version 5.4.6-1ubuntu1.3

thank you