Upgrade to version 14.04.1 failes

[Shai]

While trying to update Ubuntu from version 12.04 to 14.04.1 the upgrade process fails at the second step (Setting new software channels), at the end of the step while tying to calculate space.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: update-manager 1:0.156.14.17
ProcVersionSignature: Ubuntu 3.13.0-34.60~precise1-generic 3.13.11.4
Uname: Linux 3.13.0-34-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: amd64
Date: Sun Aug 17 06:58:18 2014
GsettingsChanges:
 com.ubuntu.update-manager first-run false
 com.ubuntu.update-manager launch-time 1408247831
 com.ubuntu.update-manager show-details true
 com.ubuntu.update-manager window-height 500
 com.ubuntu.update-manager window-width 600
InstallationMedia: Ubuntu 12.04.4 LTS "Precise Pangolin" - Release amd64 (20140204)
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_US:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
Symptom: ubuntu-release-upgrader-core
UpgradeStatus: Upgraded to precise on 2014-08-17 (0 days ago)
VarLogDistupgradeTermlog:

[Shai (tirosh)]

dist-upgrade