Al ejecutar y/o probar una encuesta me aparece la página de inicio correctamente pero al darle click en siguiente, me aparece un warning del server que dice....Forbidden

You don't have permission to access /index.php on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Todo funcionaba correctamente hasta hace un par de días atras y nada he modificado. He reinstalado todo y no consigo resolverlo. Pareciera ser un problema del webserver....

Agradeceré cualquier ayuda

Un saludo

revisando el error_log encuentro lo siguiente

[23-Feb-2012 17:56:26] PHP Warning: PHP Startup: Suhosin Extension does not officially support PHP 5.2 and below anymore, because it is discontinued. Use it at your own risk. in Unknown on line 0
[23-Feb-2012 18:00:57] PHP Warning: PHP Startup: Suhosin Extension does not officially support PHP 5.2 and below anymore, because it is discontinued. Use it at your own risk. in Unknown on line 0
[23-Feb-2012 18:44:20] PHP Warning: PHP Startup: Suhosin Extension does not officially support PHP 5.2 and below anymore, because it is discontinued. Use it at your own risk. in Unknown on line 0
[23-Feb-2012 19:02:44] PHP Warning: PHP Startup: Suhosin Extension does not officially support PHP 5.2 and below anymore, because it is discontinued. Use it at your own risk. in Unknown on line 0

Coincide con la fecha cuando comenzó el problema.

Alguna idea??