I ported a whole XEN image with ISPConfig installed to a new instance. The only variables that have changed are the IP, the hostname and the default domain. Think i have tweaked everything i should on /root/ispconfig/httpd/conf/httpd.conf and /home/admispconfig/ispconfig/lib/config.inc.php However, by the default the public IP does not redirect to the sharedip folder. Instead, it shows me the webserver root directory index (ie, /var/www). Thanks, Nuno.
Please make sure that you changed the IP address of the server also in ISPConfig under management > server > settings. Also check that you have the sharedIP vhost in your apache.conf, apache2.conf or httpd.conf file (depending on the linux distribution).