Erro de assinaturas no apt-get

[jbmacae]

Erro:

W: GPG error: http://br.archive.ubuntu.com edgy-backports Release: As seguintes assinaturas foram inválidas : BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
W: Você terá que executar apt-get update para corrigir esses arquivos faltosos

Meu sources.list:

## 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

[jbmacae]

Nossa, ninguém!!!!?