Cannot upgrade from Ubuntu 12.04 to 14.04

[eyfit]

just look at the verbouse information the installer has (supposed) to collect.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: update-manager 1:0.156.14.17
ProcVersionSignature: Ubuntu 3.2.0-67.101-generic 3.2.60
Uname: Linux 3.2.0-67-generic x86_64
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: amd64
Date: Sun Aug 24 08:38:43 2014
GsettingsChanges:

InstallationMedia: Ubuntu-Server 12.04 LTS "Precise Pangolin" - Release amd64 (20120424.1)
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_AU:en
 TERM=unknown
 PATH=(custom, no user)
 LANG=en_AU.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
Symptom: ubuntu-release-upgrader-core
UpgradeStatus: Upgraded to precise on 2014-08-23 (0 days ago)
VarLogDistupgradeAptlog:
 Log time: 2014-08-24 08:36:37.197044
 Log time: 2014-08-24 08:36:42.149600
 Log time: 2014-08-24 08:38:33.657421
 Log time: 2014-08-24 08:38:53.223690
VarLogDistupgradeTermlog: