depois de várias modificações, deixei minha sources.list dessa forma, seguindo um post do Galactus:
## Lista de repositórios Oficial##
deb http://archive.ubuntu.com/ubuntu/ edgy main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ edgy main restricted universe multiverse
## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu/ edgy-updates main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ edgy-updates main restricted universe multiverse
## Uncomment the following two lines to add software from the 'universe'
## repository.
## 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
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://br.archive.ubuntu.com/ubuntu/ edgy universe
deb-src http://br.archive.ubuntu.com/ubuntu/ edgy universe
## Uncomment the following two lines to add software from the 'backports'
## repository.
## 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://br.archive.ubuntu.com/ubuntu/ edgy-backports main restricted universe multiverse
deb-src http://br.archive.ubuntu.com/ubuntu/ edgy-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu edgy-security main restricted universe multiverse
deb-src http://security.ubuntu.com/ubuntu edgy-security main restricted universe multiverse
# deb http://security.ubuntu.com/ubuntu edgy-security universe
# deb-src http://security.ubuntu.com/ubuntu edgy-security universe
## INÍCIO DA Lista NÃO OFICIAL, use com sabedoria
## LISTEN GNOME
##Lista para instalar o Listen Gnome, player alternativo para o Amarok no Gnome. Esta lista é a de pacotes instáveis, com as versões mais recentes do Listen. É do Dapper mesmo, mas serve perfeitamente para o Edgy Eft
#deb http://theli.free.fr/packages/ dapper listen listen-unstable
#deb-src http://theli.free.fr/packages/ dapper listen listen-unstable
##Cristhian Marillat (multimidia) - Descomente apenas para instalar os codecs necessários.
## Opção alternativa do Seveas
#deb http://www.debian-multimedia.org sarge main
#deb http://www.debian-multimedia.org etch main
#deb http://www.debian-multimedia.org sid main
## Seveas
# deb http://seveas.imbrandon.com edgy-seveas all
# deb-src http://seveas.imbrandon.com edgy-seveas all
## BRASERO
## Gravador de CDs e DVDs alternativa ao Gnome Baker e K3B
# deb http://mrpouit.tuxfamily.org edgy-pouit extra
# deb-src http://mrpouit.tuxfamily.org edgy-pouit extra
porém, continuo sem conseguir selecionar as atualizações que relatei antes, e ao fazer um "sudo apt-get update" a mensagem que me é apresentada é:
felix@felix-casa:~$ sudo apt-get update
Obtendo:1 http://br.archive.ubuntu.com edgy Release.gpg [191B]
Obtendo:2 http://archive.ubuntu.com edgy Release.gpg [191B]
Atingido http://archive.ubuntu.com edgy/main Translation-pt_BR
Atingido http://br.archive.ubuntu.com edgy/universe Translation-pt_BR
Atingido http://archive.ubuntu.com edgy/restricted Translation-pt_BR
Obtendo:3 http://br.archive.ubuntu.com edgy-backports Release.gpg [191B]
Ign http://br.archive.ubuntu.com edgy-backports/main Translation-pt_BR
Atingido http://archive.ubuntu.com edgy/universe Translation-pt_BR
Ign http://br.archive.ubuntu.com edgy-backports/restricted Translation-pt_BR
Atingido http://archive.ubuntu.com edgy/multiverse Translation-pt_BR
Ign http://br.archive.ubuntu.com edgy-backports/universe Translation-pt_BR
Obtendo:4 http://archive.ubuntu.com edgy-updates Release.gpg [191B]
Ign http://archive.ubuntu.com edgy-updates/main Translation-pt_BR
Ign http://br.archive.ubuntu.com edgy-backports/multiverse Translation-pt_BR
Obtendo:5 http://security.ubuntu.com edgy-security Release.gpg [191B]
Ign http://archive.ubuntu.com edgy-updates/restricted Translation-pt_BR
Atingido http://br.archive.ubuntu.com edgy Release
Ign http://security.ubuntu.com edgy-security/main Translation-pt_BR
Ign http://archive.ubuntu.com edgy-updates/universe Translation-pt_BR
Atingido http://br.archive.ubuntu.com edgy-backports Release
Ign http://security.ubuntu.com edgy-security/restricted Translation-pt_BR
Ign http://archive.ubuntu.com edgy-updates/multiverse Translation-pt_BR
Ign http://security.ubuntu.com edgy-security/universe Translation-pt_BR
Atingido http://archive.ubuntu.com edgy Release
Atingido http://br.archive.ubuntu.com edgy/universe Packages
Ign http://security.ubuntu.com edgy-security/multiverse Translation-pt_BR
Atingido http://archive.ubuntu.com edgy-updates Release
Atingido http://br.archive.ubuntu.com edgy/universe Sources
Atingido http://security.ubuntu.com edgy-security Release
Atingido http://br.archive.ubuntu.com edgy-backports/main Packages
Atingido http://archive.ubuntu.com edgy/main Packages
Atingido http://br.archive.ubuntu.com edgy-backports/restricted Packages
Atingido http://archive.ubuntu.com edgy/restricted Packages
Atingido http://security.ubuntu.com edgy-security/main Packages
Atingido http://archive.ubuntu.com edgy/universe Packages
Atingido http://br.archive.ubuntu.com edgy-backports/universe Packages
Atingido http://br.archive.ubuntu.com edgy-backports/multiverse Packages
Atingido http://security.ubuntu.com edgy-security/restricted Packages
Atingido http://archive.ubuntu.com edgy/multiverse Packages
Obtendo:6 http://security.ubuntu.com edgy-security/universe Packages [12,0kB]
Atingido http://br.archive.ubuntu.com edgy-backports/main Sources
Atingido http://archive.ubuntu.com edgy/main Sources
Atingido http://security.ubuntu.com edgy-security/multiverse Packages
Atingido http://br.archive.ubuntu.com edgy-backports/restricted Sources
Atingido http://archive.ubuntu.com edgy/restricted Sources
Atingido http://security.ubuntu.com edgy-security/main Sources
Atingido http://br.archive.ubuntu.com edgy-backports/universe Sources
Atingido http://archive.ubuntu.com edgy/universe Sources
Atingido http://security.ubuntu.com edgy-security/restricted Sources
Atingido http://br.archive.ubuntu.com edgy-backports/multiverse Sources
Atingido http://archive.ubuntu.com edgy/multiverse Sources
Obtendo:7 http://security.ubuntu.com edgy-security/universe Sources [1476B]
Atingido http://security.ubuntu.com edgy-security/multiverse Sources
Atingido http://archive.ubuntu.com edgy-updates/main Packages
Atingido http://archive.ubuntu.com edgy-updates/restricted Packages
Atingido http://archive.ubuntu.com edgy-updates/universe Packages
Atingido http://archive.ubuntu.com edgy-updates/multiverse Packages
Obtendo:8 http://archive.ubuntu.com edgy-updates/main Sources [4227B]
Atingido http://archive.ubuntu.com edgy-updates/restricted Sources
Atingido http://archive.ubuntu.com edgy-updates/universe Sources
Atingido http://archive.ubuntu.com edgy-updates/multiverse Sources
Baixados 17,7kB em 1s (10,5kB/s)
Falha ao baixar http://archive.ubuntu.com/ubuntu/dists/edgy-updates/main/source/Sources.bz2 MD5Sum incorreto
Falha ao baixar http://security.ubuntu.com/ubuntu/dists/edgy-security/universe/binary-i386/Packages.bz2 MD5Sum incorreto
Falha ao baixar http://security.ubuntu.com/ubuntu/dists/edgy-security/universe/source/Sources.bz2 MD5Sum incorreto
Lendo Lista de Pacotes... Pronto
E: Alguns arquivos de índice falharam no download, eles foram ignorados ou os antigos foram usados em seu lugar.
felix@felix-casa:~$
alguém tem idéia do que seja?