Squid authentication problem

Hi I'm using squid from 9.2 and is setup and working fine. However I now want to authenticate against a MySQL database. The MySQL authentication program has been written, compiled and tested on it's own and works correctly. The path for this program has been appended to the authenticate_program line in squid.conf. I have also added an proxy_auth REQUIRED acl together with the corresponding http_access allow entry. authenticate_children is set to 5. However, no child processes start when squid is started. Any ideas would be helpful. -- Regards Bill Antonia Network Manager Beacon Community College North Beeches Road Crowborough East Sussex TN6 2AS Tel 01892 603000 Fax 01892 664562