Hi Till and Falko, something uncommon is happening to me. Everytime I login in the administration, after selecting one website detail page, then click on the Co-Domain tab and finally clicking on the new button the admin system log me out. This is the error code: 103. Regards.
Ok, Moved your post to the ispconfig 2 forum. Did you changed anything right before this behaviour started? Are you accessing ispconfig trough the hostname of the server or trough different domain names? Did you update your webbrowser or changed browser settings?