Problem installing packages : Hash Sum mismatch

Hello Everyone,

I am trying to install some packages (the gnome-themes-ubuntu in this case) and this is what I get when trying to install them :


aliasbody@LibreBook:~$ sudo apt-get install gnome-themes-ubuntu
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
gnome-themes-ubuntu
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 331 kB of archives.
After this operation, 2367 kB of additional disk space will be used.
Get:1 http://archive.trisquel.info/trisquel/ toutatis/main gnome-themes-ubuntu all 0.6.1 [331 kB]
Fetched 331 kB in 0s (2949 kB/s)
Failed to fetch http://archive.trisquel.info/trisquel/pool/main/g/gnome-themes-ubuntu/gnome-themes-ubuntu_0.6.1_all.deb Hash Sum mismatch
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?


This is what I get when running "sudo apt-get update"


aliasbody@LibreBook:~$ sudo apt-get update
Hit http://archive.trisquel.info toutatis Release.gpg
Hit http://archive.trisquel.info toutatis-security Release.gpg
Hit http://archive.trisquel.info toutatis-updates Release.gpg
Hit http://archive.trisquel.info toutatis-backports Release.gpg
Hit http://archive.trisquel.info toutatis Release
Hit http://archive.trisquel.info toutatis-security Release
Hit http://archive.trisquel.info toutatis-updates Release
Hit http://archive.trisquel.info toutatis-backports Release
Hit http://archive.trisquel.info toutatis/main Sources
Hit http://archive.trisquel.info toutatis/main amd64 Packages
Hit http://archive.trisquel.info toutatis/main i386 Packages
Ign http://archive.trisquel.info toutatis/main TranslationIndex
Hit http://archive.trisquel.info toutatis-security/main Sources
Hit http://archive.trisquel.info toutatis-security/main amd64 Packages
Hit http://archive.trisquel.info toutatis-security/main i386 Packages
Ign http://archive.trisquel.info toutatis-security/main TranslationIndex
Hit http://archive.trisquel.info toutatis-updates/main Sources
Hit http://archive.trisquel.info toutatis-updates/main amd64 Packages
Hit http://archive.trisquel.info toutatis-updates/main i386 Packages
Ign http://archive.trisquel.info toutatis-updates/main TranslationIndex
Hit http://archive.trisquel.info toutatis-backports/main amd64 Packages
Hit http://archive.trisquel.info toutatis-backports/main i386 Packages
Ign http://archive.trisquel.info toutatis-backports/main TranslationIndex
Ign http://archive.trisquel.info toutatis/main Translation-en_US
Ign http://archive.trisquel.info toutatis/main Translation-en
Ign http://archive.trisquel.info toutatis-security/main Translation-en_US
Ign http://archive.trisquel.info toutatis-security/main Translation-en
Ign http://archive.trisquel.info toutatis-updates/main Translation-en_US
Ign http://archive.trisquel.info toutatis-updates/main Translation-en
Ign http://archive.trisquel.info toutatis-backports/main Translation-en_US
Ign http://archive.trisquel.info toutatis-backports/main Translation-en
Reading package lists... Done