O Update Manager da o seguinte erro ao tentar actualizar:

[calotas]

Quando tento correr o Update manager para fazer as actualizações no ubuntu, aparece a seguinte mensagem de erro:

"
Could not download all repository indexes

The repository might be no longer available or could not be contacted because of network problems. If available an older version of the failed index will be used. Otherwise the repository will be ignored. Check your network connection and the correct writing of the repository address in the preferences.

http://archive.ubuntu.com/ubuntu/dists/dapper-updates/restricted/binary-i386/Packages.bz2: Sub-process bzip2 returned an error code (2)
http://archive.ubuntu.com/ubuntu/dists/dapper-backports/restricted/binary-i386/Packages.bz2: Sub-process bzip2 returned an error code (2

"
De seguida, quando tento fechar o Update Manager, aparece a seguinte mensagem:

"

The following problems were found on your system:

W: Duplicate sources.list entry http://archive.ubuntu.com dapper/main Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper_main_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper/restricted Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper_restricted_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper/universe Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper_universe_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper/multiverse Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper_multiverse_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper-security/main Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper-security_main_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper-security/restricted Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper-security_restricted_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper-security/universe Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper-security_universe_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper-security/multiverse Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper-security_multiverse_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper-updates/main Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper-updates_main_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper-updates/restricted Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper-updates_restricted_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper-updates/universe Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper-updates_universe_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper-updates/multiverse Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper-updates_multiverse_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper-backports/main Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper-backports_main_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper-backports/restricted Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper-backports_restricted_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper-backports/universe Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper-backports_universe_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com dapper-backports/multiverse Packages (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper-backports_multiverse_binary-i386_Packages)

"


Bom, parece ser um erro bem grave, mas n percebo o que fazer para resolver isso.

Alguém me pode ajudar???

Aguardo Resposta.

Obrigado