cron job for php not working

Hi there, I am trying to install following cron job: 0 6 * * * php /home/www/project/app_cron/follow_up_new_members.php The script works, if I run this "php /home..." line manually it works out, but it does not automaticaly at 6 am as supposed. I do also see in /var/log/messages that the cron job has happened at that time, but the file did not generate the emails like it supposed to. I am running the crontab as webserver user. Thanx for any helpful ideas on that, Merlin