Impossible to upgarde from 10.04 to 10.10 (unresolvable problem occurred)

[naoli]

Binary package hint: update-manager

When trying to upgrade to 10.10, here's what I got :

_______________________________
  Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade:Resolve generated breaks, this may be
caused by held packages.

 This can be caused by:
 * Upgrading to a pre-release version of Ubuntu
 * Running the current pre-release version of Ubuntu
 * Unofficial software packages not provided by Ubuntu

If none of this applies, then please report this bug against the 'update-manager' package and include the files in /var/log/dist-upgrade/ in the bug report.
______________________________

I tried to run update-manager -c -d as deviced in other posts, no improvement.

The apt.log speaks about " Try to Re-Instate xserver-xorg-" but I got no clue.

________________________________
% apt-cache policy update-manager
update-manager:
  Installé : 1:0.134.11
  Candidat : 1:0.142.20
 Table de version :
     1:0.142.20 0
        500 http://fr.archive.ubuntu.com/ubuntu/ maverick-updates/main Packages
     1:0.142.19 0
        500 http://fr.archive.ubuntu.com/ubuntu/ maverick/main Packages
 *** 1:0.134.11 0
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: update-manager 1:0.134.11
ProcVersionSignature: Ubuntu 2.6.32-26.48-generic 2.6.32.24+drm33.11
Uname: Linux 2.6.32-26-generic x86_64
Architecture: amd64
Date: Tue Dec 21 11:35:06 2010
ExecutablePath: /usr/bin/update-manager
InterpreterPath: /usr/bin/python2.6
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=
 PATH=(custom, user)
 LANG=fr_FR.UTF-8
 SHELL=/bin/zsh
SourcePackage: update-manager

[naoli (naoli)]

OK sorry, seems duplicate of https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/606652