Thanks for the swift reply. I asked to install the default which was SSH server and (I can't remember the name exactly, but it was the bottom item in the list) system tools or core tools.
I started again from scratch then mounted the virtual disk on another VM to inspect it. I've extracted the file /var/log/installer/syslog which is 18K when bzip2'd - please may I send it directly to you, Samuel, rather than to the list? I can also send the whole contents of /var/log/installer but that's rather bigger.
Peter