Got this error while I was trying to configure Joomla to work with suPHP. This is the config I`m using to make it work:

ServerAdmin aa@aa.com
ServerName www.site.org
ServerAlias site.org
DocumentRoot /home/virtuals/www.site.org/public_html/
ErrorLog /home/virtuals/www.site.org/logs/error.log
CustomLog /home/virtuals/www.site.org/logs/access.log combined
ServerSignature On
php_admin_flag safe_mode Off
php_admin_flag register_globals On
php_admin_value open_basedir /home/virtuals/www.site.org/public_html:/tmp

AllowOverride All
Allow from All
Options Indexes FollowSymLinks



php_admin_flag engine on
suPHP_Engine on
AddHandler php5-script .php
php_admin_flag engine on