upgrade from 13.10 to 14.04 failed

[smugas]

failed with message:
An unresolvable problem occurred while calculating the upgrade.

 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

Jeśli żadna z wymienionych sytuacji nie ma miejsca, proszę zgłosić ten błąd wprowadzając w terminalu polecenie „ubuntu-bug ubuntu-release-upgrader-core”.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: ubuntu-release-upgrader-core 1:0.205.6
ProcVersionSignature: Ubuntu 3.11.0-20.35-generic 3.11.10.6
Uname: Linux 3.11.0-20-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.12.5-0ubuntu2.2
Architecture: amd64
CrashDB: ubuntu
Date: Sat May 24 09:35:26 2014
InstallationDate: Installed on 2011-02-27 (1181 days ago)
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
MarkForUpload: True
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to saucy on 2014-05-24 (0 days ago)
VarLogDistupgradeTermlog: