W: Failed to fetch http://ppa.launchpad.net/nginx/development/ubuntu/dists/precise/main/source/Sources  Hash Sum mismatch

W: Failed to fetch http://ppa.launchpad.net/nginx/development/ubuntu/dists/precise/main/binary-amd64/Packages  Hash Sum mismatch

W: Failed to fetch http://ppa.launchpad.net/nginx/development/ubuntu/dists/precise/main/binary-i386/Packages  Hash Sum mismatch

W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/precise-security/main/source/Sources  Hash Sum mismatch

W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/precise-security/main/binary-amd64/Packages  Hash Sum mismatch

W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/precise-security/main/binary-i386/Packages  Hash Sum mismatch

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