Unable to update / upgrade any ubuntu security updates. Update manager on ubuntu desktop hangs. As well as 'apt-get upgrade' & 'apt-get dist-upgrade' hanging on server versions.

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Unable to update / upgrade any ubuntu security updates. Update manager on ubuntu desktop hangs. As well as 'apt-get upgrade' & 'apt-get dist-upgrade' hanging on server versions.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: apt-listchanges (not installed)
ProcVersionSignature: Ubuntu 3.8.0-35.52~precise1-generic 3.8.13.13
Uname: Linux 3.8.0-35-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: amd64
Date: Tue Feb 4 20:02:19 2014
InstallationMedia: Ubuntu 12.04.3 LTS "Precise Pangolin" - Release amd64 (20130820.1)
MarkForUpload: True
ProcEnviron:
 LANGUAGE=en_GB:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: apt-listchanges
UpgradeStatus: No upgrade log present (probably fresh install)
modified.conffile..etc.apt.apt.conf.d.20listchanges: [deleted]