"ubuntu-minimal cannot be found anymore" during upgrade from 10.04 t0 10.10

[Michael Doube]

Binary package hint: update-manager

Upgrading from 10.04 to 10.10 via update manager fails with this error message:

Invalid package information

After your package information was updated the essential package 'ubuntu-minimal' can not be found anymore.
This indicates a serious error, please report this bug against the 'update-manager' package and include the files in /var/log/dist-upgrade/ in the bug report.
---
Architecture: amd64
DistroRelease: Ubuntu 10.04
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Alpha amd64 (20100412)
Package: update-manager 1:0.134.10
PackageArchitecture: all
ProcEnviron:
 LANG=en_GB.utf8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.32-25.44-generic 2.6.32.21+drm33.7
Tags: lucid
Uname: Linux 2.6.32-25-generic x86_64
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[Michael Doube (michael-doube)]

apport information

[Michael Doube (michael-doube)]

Fixed / worked around bug by ejecting 10.10 CDROM, just downloaded from the torrent, and changing apt sources to somewhere nearer in France, not Canonical's London servers.

[Jon Vaughan (jsvaughan)]

Is this a duplicate of https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/631426 ?