there is a problem when I press the "check" button at update manager.

W:Failed to fetch http://ppa.launchpad.net/kamalmostafa/linux-kamal-mjgbacklight/ubuntu/dists/precise/main/binary-i386/Packages 404 Not Found, E:Some index files failed to download. They have been ignored, or old ones used instead.

I saw this message when I press the "check" button after update, before upgrade.
I tried to upgrade my ubuntu at terminal. but there is same problem. I cannot solve it.
I'm not expert. I need person to solve this problem.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: update-manager 1:0.134.12.1
ProcVersionSignature: Ubuntu 2.6.32-43.97-generic 2.6.32.59+drm33.24
Uname: Linux 2.6.32-43-generic i686
Architecture: i386
Date: Wed Sep 26 21:45:08 2012
GConfNonDefault:
 /apps/update-manager/check_new_release_ignore=
 /apps/update-manager/first_run=false
 /apps/update-manager/show_details=false
 /apps/update-manager/show_versions=false
 /apps/update-manager/window_size=(600,544)
InstallationMedia: Ubuntu 10.04.3 LTS "Lucid Lynx" - Release i386 (20110720.1)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=ko_KR.utf8
 SHELL=/bin/bash
SourcePackage: update-manager
VarLogDistupgradeAptclonesystemstate.tar.gz: Error: [Errno 13] Permission denied: '/var/log/dist-upgrade/apt-clone_system_state.tar.gz'
VarLogDistupgradeTermlog: