Failed to download package files and cannot update

I have been following this source: PackageManagerTroubleshootingProcedure at step 5:

LANG=C;sudo apt-get update -o APT::Cache-Limit=100000000 && sudo apt-get dist-upgrade

every update runs well, except:

The following NEW packages will be installed:
  linux-image-3.2.0-52-generic-pae
The following packages will be upgraded:
  firefox libreoffice-base-core libreoffice-calc libreoffice-common
  libreoffice-core libreoffice-draw libreoffice-gnome libreoffice-gtk
  libreoffice-help-en-us libreoffice-impress libreoffice-math
  libreoffice-writer linux-firmware linux-generic-pae linux-image-generic-pae
  python-uno thunderbird thunderbird-globalmenu thunderbird-gnome-support
19 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 170 MB/199 MB of archives.
After this operation, 136 MB of additional disk space will be used.
Do you want to continue [Y/n]? y
Err http://archive.ubuntu.com/ubuntu/ precise-updates/main libreoffice-common all 1:3.5.7-0ubuntu4
  403 Forbidden [IP: 91.189.91.15 80]
Err http://archive.ubuntu.com/ubuntu/ precise-updates/main libreoffice-core i386 1:3.5.7-0ubuntu4
  403 Forbidden [IP: 91.189.91.15 80]
Err http://archive.ubuntu.com/ubuntu/ precise-security/main linux-image-3.2.0-52-generic-pae i386 3.2.0-52.78
  403 Forbidden [IP: 91.189.91.15 80]
Err http://archive.ubuntu.com/ubuntu/ precise-security/main firefox i386 23.0+build2-0ubuntu0.12.04.1
  403 Forbidden [IP: 91.189.91.15 80]
Err http://archive.ubuntu.com/ubuntu/ precise-security/main linux-firmware all 1.79.6
  403 Forbidden [IP: 91.189.91.15 80]
Err http://archive.ubuntu.com/ubuntu/ precise-security/main thunderbird i386 17.0.8+build1-0ubuntu0.12.04.1
  403 Forbidden [IP: 91.189.91.15 80]
Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/libr/libreoffice/libreoffice-common_3.5.7-0ubuntu4_all.deb 403 Forbidden [IP: 91.189.91.15 80]
Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/libr/libreoffice/libreoffice-core_3.5.7-0ubuntu4_i386.deb 403 Forbidden [IP: 91.189.91.15 80]
Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/l/linux/linux-image-3.2.0-52-generic-pae_3.2.0-52.78_i386.deb 403 Forbidden [IP: 91.189.91.15 80]
Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/f/firefox/firefox_23.0+build2-0ubuntu0.12.04.1_i386.deb 403 Forbidden [IP: 91.189.91.15 80]
Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/l/linux-firmware/linux-firmware_1.79.6_all.deb 403 Forbidden [IP: 91.189.91.15 80]
Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/t/thunderbird/thunderbird_17.0.8+build1-0ubuntu0.12.04.1_i386.deb 403 Forbidden [IP: 91.189.91.15 80]

Eventhough i already try--fix-missing + reboot. This same case happen again.
i do have a problem with "cat: /etc/apt/apt.conf: No such file or directory" is this fatal to my 403 Forbidden?