cannot upgrade to ubuntu 11.10

[Kim Bertmeyer]

Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade:
E:Error, pkgProblemResolver::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 using the command 'ubuntu-bug update-manager' in a terminal.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: update-manager 1:0.150.3
ProcVersionSignature: Ubuntu 2.6.38-11.50-generic 2.6.38.8
Uname: Linux 2.6.38-11-generic i686
NonfreeKernelModules: nvidia
Architecture: i386
Date: Fri Jan 27 16:08:01 2012
DpkgHistoryLog.txt:

DpkgTerminalLog.txt:

GConfNonDefault:
 /apps/update-manager/check_new_release_ignore=oneiric
 /apps/update-manager/first_run=false
 /apps/update-manager/show_details=true
 /apps/update-manager/window_size=(600,600)
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
UpgradeStatus: Upgraded to natty on 2012-01-27 (0 days ago)

[RedSingularity (redsingularity)]

Please attach the directory:

/var/log/dist-upgrade

Thanks.
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