Bind configuration problem
On a clean install of ISPConfig3 on Debian Wheezy following the perfect server tutorial (http://www.howtoforge.com/perfect-server-debian-wheezy-apache2-bind-dovecot-ispconfig-3), the bind configuration has a serious problem: the port 53 is closed by default.
I had to edit the file named.conf.options and add the line
listen-on port 53 { any; };
in order to open the port.
Now the server resolves.