Ok, it worked, but I had to hack the installer so it didn't overwrite /etc/apt/sources.list. I added the deb-cache directory myself, dist-upgraded, and then ran the installer from the command line. Now its "setting up my computer to act as a Media Director".
Suggestion for Paul: have the installer make backups of critical system files (such as sources.list, interfaces, etc.). Some of us are running the installer on our workstations in order to test it, and it basically screws many things up.