update says cannot calculate

[Jason]

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

Note from updater

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: ubuntu-release-upgrader-core 1:0.205.6
ProcVersionSignature: Ubuntu 3.11.0-23.40-generic 3.11.10.10
Uname: Linux 3.11.0-23-generic i686
ApportVersion: 2.12.5-0ubuntu2.2
Architecture: i386
CrashDB: ubuntu
Date: Mon Jun 9 11:44:19 2014
InstallationDate: Installed on 2014-03-07 (94 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release i386 (20131016.1)
MarkForUpload: True
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to saucy on 2014-06-09 (0 days ago)
VarLogDistupgradeTermlog: