Ubuntu 64-bit & ldquo; Не удалось извлечь файл [..] binary-i386 / Packages & rdquo; ошибка при обновлении apt repos

У меня есть следующая проблема на Ubuntu 12.04 LTS на 64-битной машине: всякий раз, когда я пытаюсь обновить репозитории aptitude, обновление будет странно терпеть неудачу с ошибкой, связанной с i386. Я предполагаю, что это не должно происходить в 64-битной системе.

root@liv-HP-Compaq-dc7900:/home/liv# apt-get update
Ign file: apt-build Release.gpg
Get:1 file: apt-build Release [107 B]                                          
Ign file: apt-build/main TranslationIndex                                      
Err file: apt-build/main i386 Packages                                         
  File not found
[..]
W: Failed to fetch file:/var/cache/apt-build/repository/dists/apt-build/main/binary-i386/Packages  File not found

E: Some index files failed to download. They have been ignored, or old ones used instead.

Я попытался восстановить status-old без везения:

sudo cp /var/lib/dpkg/status-old /var/lib/dpkg/status [!d3 ]

Я также попытался:

root@liv-HP-Compaq-dc7900:/home/liv# apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 90 not upgraded.

Но, похоже, он ничего не делает или не сообщает ничего полезного. Каждая последующая apt-get update заканчивается ошибкой.

Для записи мой файл /etc/apt/sources.list выглядит так:

# deb cdrom:[Xubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ dists/precise/main/binary-i386/

# deb cdrom:[Xubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ dists/precise/multiverse/binary-i386/
# deb cdrom:[Xubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ dists/precise/restricted/binary-i386/
# deb cdrom:[Xubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ dists/precise/universe/binary-i386/
# deb cdrom:[Xubuntu 12.04 LTS _Precise Pangolin_ - Release amd64 (20120425)]/ precise main multiverse restricted universe

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://nl.archive.ubuntu.com/ubuntu/ precise main restricted
deb-src http://nl.archive.ubuntu.com/ubuntu/ precise main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://nl.archive.ubuntu.com/ubuntu/ precise-updates main restricted
deb-src http://nl.archive.ubuntu.com/ubuntu/ precise-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://nl.archive.ubuntu.com/ubuntu/ precise universe
deb-src http://nl.archive.ubuntu.com/ubuntu/ precise universe
deb http://nl.archive.ubuntu.com/ubuntu/ precise-updates universe
deb-src http://nl.archive.ubuntu.com/ubuntu/ precise-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://nl.archive.ubuntu.com/ubuntu/ precise multiverse
deb-src http://nl.archive.ubuntu.com/ubuntu/ precise multiverse
deb http://nl.archive.ubuntu.com/ubuntu/ precise-updates multiverse
deb-src http://nl.archive.ubuntu.com/ubuntu/ precise-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://nl.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse
deb-src http://nl.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu precise-security main restricted
deb-src http://security.ubuntu.com/ubuntu precise-security main restricted
deb http://security.ubuntu.com/ubuntu precise-security universe
deb-src http://security.ubuntu.com/ubuntu precise-security universe
deb http://security.ubuntu.com/ubuntu precise-security multiverse
deb-src http://security.ubuntu.com/ubuntu precise-security multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu precise partner
# deb-src http://archive.canonical.com/ubuntu precise partner

## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://extras.ubuntu.com/ubuntu precise main
deb-src http://extras.ubuntu.com/ubuntu precise main
deb http://cran.at.r-project.org/bin/linux/ubuntu precise/
# deb-src http://cran.at.r-project.org/bin/linux/ubuntu precise/
# deb http://archive.canonical.com/ precise partner
# deb-src http://archive.canonical.com/ precise partner

И используемое ядро:

liv@liv-HP-Compaq-dc7900:~$ uname -a
Linux liv-HP-Compaq-dc7900 3.2.0-57-generic #87-Ubuntu SMP Tue Nov 12 21:35:10 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

Что не так и как я могу это исправить?