Lucid to Maverick LTSP: Could not calculate the upgrade

[gcc]

Binary package hint: update-manager

Update-manager says:

Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade.

Please report this bug against the 'update-manager' package and include the following error message:
'E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.'

apt.log ends with:

Investigating cups
Package cups has broken Depends on cups-ppdc
Done

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: update-manager 1:0.134.10
ProcVersionSignature: Ubuntu 2.6.32-24.39-generic 2.6.32.15+drm33.5
Uname: Linux 2.6.32-24-generic i686
Architecture: i386
Date: Tue Dec 7 15:14:11 2010
InstallationMedia: Ubuntu 10.04.1 LTS "Lucid Lynx" - Release i386 (20100816.1)
PackageArchitecture: all
ProcEnviron:
 LANG=en_US.utf8
 SHELL=/bin/bash
SourcePackage: update-manager

[RedSingularity (redsingularity)]

Duplicate of bug 614993. Marking.