Adding php5.ini doesn't work at all. But see the 'Disable FastCGI' section in this article on GoDaddy: http://support.godaddy.com/help/article/5121/changing-your-hosting-accounts-file-extensions
Add these lines to .htaccess files (webroot & website installation directory):
Options +ExecCGI
addhandler x-httpd-php5-cgi .php
It saves me a day! Cheers! Thanks DragonLord!