Open /etc/suphp.conf...
vi /etc/suphp.conf
... and make sure that it contains x-httpd-suphp instead of x-httpd-php towards the end of the file:
Code:
[...]
[handlers]
;Handler for php-scripts
;x-httpd-php="php:/usr/bin/php-cgi5"
x-httpd-suphp="php:/usr/bin/php-cgi5"
[...]