Unable to upgrade to 12.04 TLS from 10.04.4 TLS

[NamKyu Kim]

Looks like it fails to upgrade due to the 3rd party application installed on my machine.
However, I'm on 10.04.4 TLS and just tried to upgrade it to 12.04 TLS. but, after the package manager check the packages and the size of the new packages, it prints an error pop-up windows saying "unable to calculate the size" in Korean.

And though tried several times, it failed always.

Thanks,
NamKyu

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: update-manager 1:0.134.12.1
ProcVersionSignature: Ubuntu 2.6.32-40.87-generic 2.6.32.57+drm33.23
Uname: Linux 2.6.32-40-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Sat Mar 30 11:26:00 2013
GConfNonDefault:
 /apps/update-manager/check_new_release_ignore=
 /apps/update-manager/first_run=false
 /apps/update-manager/show_versions=false
 /apps/update-manager/window_size=(600,923)
InstallationMedia: Ubuntu 10.04.1 LTS "Lucid Lynx" - Release amd64 (20100816.1)
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, no user)
 LANG=ko_KR.utf8
 SHELL=/bin/bash
SourcePackage: update-manager
VarLogDistupgradeAptclonesystemstate.tar.gz: Error: [Errno 13] 허가 거부: '/var/log/dist-upgrade/apt-clone_system_state.tar.gz'
VarLogDistupgradeTermlog:

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[dino99 (9d9)]

This version is no more supported