error during upgrade to ubuntu 14.4

[kualmente]

W:Impossibile recuperare bzip2:/var/lib/apt/lists/partial/it.archive.ubuntu.com_ubuntu_dists_trusty-updates_main_source_Sources Somma hash non corrispondente
, W:Impossibile recuperare bzip2:/var/lib/apt/lists/partial/it.archive.ubuntu.com_ubuntu_dists_trusty-updates_universe_source_Sources Somma hash non corrispondente
, W:Impossibile recuperare bzip2:/var/lib/apt/lists/partial/it.archive.ubuntu.com_ubuntu_dists_trusty-updates_multiverse_source_Sources Somma hash non corrispondente
, W:Impossibile recuperare bzip2:/var/lib/apt/lists/partial/it.archive.ubuntu.com_ubuntu_dists_trusty-backports_main_source_Sources Somma hash non corrispondente
, E:Impossibile scaricare alcuni file di indice: saranno ignorati o verranno usati quelli vecchi.

[Brian Murray (brian-murray)]

This is an error with the files becoming corrupt on your disk or during the download process. Try manually removing all the files in /var/lib/apt/lists/partial/ and then upgrading again.

[Brian Murray (brian-murray)]

Thank you for taking the time to report this issue and helping to make Ubuntu better. Examining the information you have given us, this does not appear to be a bug report so we are closing it and converting it to a question in the support tracker. We appreciate the difficulties you are facing, but it would make more sense to raise problems you are having in the support tracker at https://answers.launchpad.net/ubuntu if you are uncertain if they are bugs. For help on reporting bugs, see https://help.ubuntu.com/community/ReportingBugs#When%20not%20to%20file%20a%20bug.