update error

#This are comments entered on pastebin' s textbox
#2012.12.19 11.38
#These are the output errors of "sudo apt-get dist-upgrade"

$ sudo apt-get dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
W: Duplicate sources.list entry http://ftp.ccc.uba.ar/pub/linux/ubuntu/ precise/main i386 Packages (/var/lib/apt/lists/ftp.ccc.uba.ar_pub_linux_ubuntu_dists_precise_main_binary-i386_Packages)
W: Duplicate sources.list entry http://ftp.ccc.uba.ar/pub/linux/ubuntu/ precise/restricted i386 Packages (/var/lib/apt/lists/ftp.ccc.uba.ar_pub_linux_ubuntu_dists_precise_restricted_binary-i386_Packages)
W: You may want to run apt-get update to correct these problems

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#And below is the final output of "sudo apt-get update"

Fetched 17.6 MB in 26s (666 kB/s)
W: Failed to fetch ftp://ftp.ccc.uba.ar/linux/ubuntu/dists/precise/restricted/source/Sources  Unable to fetch file, server said '/linux/ubuntu/dists/precise/restricted/source/Sources: No existe el fichero o el directorio  '

W: Failed to fetch ftp://ftp.ccc.uba.ar/linux/ubuntu/dists/precise/main/source/Sources  Unable to fetch file, server said '/linux/ubuntu/dists/precise/main/source/Sources: No existe el fichero o el directorio  '

W: Failed to fetch ftp://ftp.ccc.uba.ar/linux/ubuntu/dists/precise/multiverse/source/Sources  Unable to fetch file, server said '/linux/ubuntu/dists/precise/multiverse/source/Sources: No existe el fichero o el directorio  '

W: Failed to fetch ftp://ftp.ccc.uba.ar/linux/ubuntu/dists/precise/universe/source/Sources  Unable to fetch file, server said '/linux/ubuntu/dists/precise/universe/source/Sources: No existe el fichero o el directorio  '

W: Failed to fetch ftp://ftp.ccc.uba.ar/linux/ubuntu/dists/precise/main/binary-i386/Packages  Unable to fetch file, server said '/linux/ubuntu/dists/precise/main/binary-i386/Packages: No existe el fichero o el directorio  '

W: Failed to fetch ftp://ftp.ccc.uba.ar/linux/ubuntu/dists/precise/restricted/binary-i386/Packages  Unable to fetch file, server said '/linux/ubuntu/dists/precise/restricted/binary-i386/Packages: No existe el fichero o el directorio  '

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

##############################################################################################

#Similar thing happened with "sudo apt-get -f update"

Fetched 17.9 MB in 35s (506 kB/s)
W: Failed to fetch ftp://ftp.ccc.uba.ar/linux/ubuntu/dists/precise/restricted/source/Sources  Unable to fetch file, server said '/linux/ubuntu/dists/precise/restricted/source/Sources: No existe el fichero o el directorio  '

W: Failed to fetch ftp://ftp.ccc.uba.ar/linux/ubuntu/dists/precise/main/source/Sources  Unable to fetch file, server said '/linux/ubuntu/dists/precise/main/source/Sources: No existe el fichero o el directorio  '

W: Failed to fetch ftp://ftp.ccc.uba.ar/linux/ubuntu/dists/precise/multiverse/source/Sources  Unable to fetch file, server said '/linux/ubuntu/dists/precise/multiverse/source/Sources: No existe el fichero o el directorio  '

W: Failed to fetch ftp://ftp.ccc.uba.ar/linux/ubuntu/dists/precise/universe/source/Sources  Unable to fetch file, server said '/linux/ubuntu/dists/precise/universe/source/Sources: No existe el fichero o el directorio  '

W: Failed to fetch ftp://ftp.ccc.uba.ar/linux/ubuntu/dists/precise/main/binary-i386/Packages  Unable to fetch file, server said '/linux/ubuntu/dists/precise/main/binary-i386/Packages: No existe el fichero o el directorio  '

W: Failed to fetch ftp://ftp.ccc.uba.ar/linux/ubuntu/dists/precise/restricted/binary-i386/Packages  Unable to fetch file, server said '/linux/ubuntu/dists/precise/restricted/binary-i386/Packages: No existe el fichero o el directorio  '

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