piektro on "[Theme: Corpo] Theme with PHP 5.3"

Hi,

I have a fresh WP 3.6 install, everything working with the default theme. After installing the Corpo theme the front site works fine but the admin gets a 500 Error "The server encountered an internal error or misconfiguration and was unable to complete your request"

I checked the server log and the error is:
wp-admin/index.php <b>Security Alert!</b> The PHP CGI cannot be accessed directly.

The problem gets solved by switching to PHP5.2, unfortunately i have to use PHP5.3 due to other running applications.

Any pointers to a solution will be appreciated, I really like your theme.