When I tried to log from Fedora Management Console the first time, it didn't work. All I got was a HTTP 404 "Not found" error.
Checking the /var/log/apache2/error.log file showed that apache was trying to serve /var/www/admin-serv which didn't exist. When the machine booted, there was also an error when apache2 started: "VirtualHost _default_:8443 --mixing * ports and non-* ports with a NameVirtualHost address is not supported..."
I am not proud to say that it took me days to overcome this. It took me installing and setting up a Fedora 8 server (because I thought the problem was related to running FDS on Ubuntu) only to find that I got the exact same HTTP 404 "Not found" error logging on to the Fedora server from the Management console.
It may well be that there was more than one problem with the Ubuntu installation - when I have time I will go back and check. To connect to the Fedora server I eventually found that all I had to do was specify the port number used when I ran setup-ds-admin.pl.