Thank you for the helpful response and Welcome to the Forum.
It was one of the Mirrors which had the wrong file made available as the Community version.
As I write, a different mirror is much more slowly downloading the fuller version, saying that it will take another four hours over my 3.8Mbps
connection, only running at sub 30Kbps. (Amendment file advice noted.)
I can see why other mirrors are being sought. Kent University is usually
a good UK site, but is not on offer for LinuxMint.
The KDE/Gnome hybrid interface is interesting and quite good so I am
looking forward to further exploration on a triple-boot PC with WinXP and
WinVista Home Premium, concentrating on data exchange problems.
MP3, M3U, MPG and MP4 file playing is immediately friendly, with CSS decoding already included.