- FPM socket permissions need to be 660 also under Apache, otherwise you get the following error:

[Sun Jun 01 18:52:24 2014] [error] [client 146.52.61.243] (13)Permission denied: FastCGI: failed to connect to server "/var/www/clients/client1/web2/cgi-bin/php5-fcgi-1.2.3.4-80-example.de": connect() failed
[Sun Jun 01 18:52:24 2014] [error] [client 146.52.61.243] FastCGI: incomplete headers (0 bytes) received from server "/var/www/clients/client1/web2/cgi-bin/php5-fcgi-1.2.3.4-80-example.de"