No puedo actualizar por un error de lista en ubuntu 12.04 y ubuntu 12.10

Hola,

Acabo de formater, instalar ubuntu 12.04 y actualizar a ubuntu 12.10. Y me aparece este error. El que me aparecia incluso antes de que formatease en el ubuntu 12.04 que tenia.

Reading package lists... Error!
W: GPG error: http://security.ubuntu.com quantal-security Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key
W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://extras.ubuntu.com quantal Release: The following signatures were invalid: BADSIG 16126D3A3E5C1192 Ubuntu Extras Archive Automatic Signing Key

W: GPG error: http://mx.archive.ubuntu.com quantal Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key
W: GPG error: http://mx.archive.ubuntu.com quantal-backports Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/quantal/Release
W: Some index files failed to download. They have been ignored, or old ones used instead.
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/mx.archive.ubuntu.com_ubuntu_dists_quantal_main_i1 8n_Translation-en%5fUS
E: The package lists or status file could not be parsed or opened.

ya intenté
sudo rm /var/lib/apt/lists/mx.archive.ubuntu.com_ubuntu_dists_quantal_main_i1 8n_Translation-en

para ver si lo removia. La terminal no me decia nada, como si estuviese bien.
Tambien verifique la lista /etc/apt/sources.list para ver si estaba bien, que no tuviese direcciones antigüas o erradas, parece estar bien. Pero al poner sudo apt-get install -f o sudo apt-get update el mensaje que les mencione arriba aparece.

-Salvador