[SOLVED] Could not download all repository indexes

If updating your software gives you one of the following problems

Could not download all repository indexes

The repository may no longer be 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 ensure the repository address in the preferences is correct.

Could not refresh the list of packages

ERROR###ERROR###ERROR###ERROR###ERROR###ERROR###ERROR

W:Failed to fetch http://packages.medibuntu.org/dists/precise/Release.gpg  Could not connect to packages.medibuntu.org:80 (67.215.66.132). - connect (110: Connection timed out),

W:Failed to fetch http://packages.medibuntu.org/dists/precise/free/binary-amd64/Packages

Unable to connect to packages.medibuntu.org:http:

Ign http://packages.medibuntu.org precise Release          

Ign http://packages.medibuntu.org precise/free amd64 Packages/DiffIndex

Err http://packages.medibuntu.org precise/free amd64 Packages

  Unable to connect to packages.medibuntu.org:http:

W: Failed to fetch http://packages.medibuntu.org/dists/precise/Release.gpg  Could not connect to packages.medibuntu.org:80 (67.215.66.132). - connect (110: Connection timed out)

W: Failed to fetch http://packages.medibuntu.org/dists/precise/free/binary-amd64/Packages  Unable to connect to packages.medibuntu.org:http:

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

it's because medibuntu packages are no more available, and thus can't be updated, but are not automatically removed from the packages which have to be updated. With this single command that I found here you can definitively eliminate this annoying problem: in a terminal type

sudo sed -i '/^deb http:\/\/packages.medibuntu.org*/d' /etc/apt/sources.list /etc/apt/sources.list.d/*.list

insert your login password, and it's done! =)