Xubuntu 10.04 to 12.04 upgrade installs unity and gnome

Hi,

I'm doing an upgrade test in a vm from Xubuntu 10.04 (up-to-date) to 12.04 (today, 2012-03-14), and what update-manager proposes me is a bit messy: 600+ new packages to install, including unity and gnome sessions, which obviously I don't want on Xubuntu (and the bandwidth waste...).

(Hopefully apport will DTRT and attach the correct logs...)

From a quick look at apt.log, the trigger for that seems to be:

> Installing indicator-applet as Recommande of indicator-messages

But we already recommend a provider of 'indicator-renderer' in xubuntu-desktop:

> new important dependency: xfce4-indicator-plugin:amd64
> Installing xfce4-indicator-plugin as Recommande of xubuntu-desktop

... not sure why update-manager chooses to install *both* of them.

Because of that, we have a nice cascading effect:

> Installing gnome-panel as Dépend of indicator-applet

[...]

> Installing gnome-applets as Recommande of gnome-panel

[...]

> Installing gnome-session as Recommande of gnome-panel

[...]

> Installing unity as Recommande of gnome-session

I guess you get the idea. ;-)
Thanks.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: update-manager 1:0.134.12.1
ProcVersionSignature: Ubuntu 2.6.32-39.86-generic 2.6.32.56+drm33.22
Uname: Linux 2.6.32-39-generic x86_64
Architecture: amd64
Date: Wed Mar 14 12:28:39 2012
GConfNonDefault:
 /apps/update-manager/check_new_release_ignore=
 /apps/update-manager/first_run=false
 /apps/update-manager/show_details=false
 /apps/update-manager/show_versions=false
 /apps/update-manager/window_size=(600,524)
InstallationMedia: Xubuntu 10.04.2 "Lucid Lynx" - Release amd64 (20110215.1)
PackageArchitecture: all
ProcEnviron:
 LANG=fr_FR.utf8
 SHELL=/bin/bash
SourcePackage: update-manager
VarLogDistupgradeTermlog: