I have been trying to install a few different server tools and i think i have generated a few error along the way. However, now i can't use sudo apt-get update. The process ends like this:
Ign http://no.archive.ubuntu.com quantal-updates/universe Translation-en_US
Ign http://no.archive.ubuntu.com quantal-backports/main Translation-en_US
Ign http://no.archive.ubuntu.com quantal-backports/multiverse Translation-en_US
Ign http://no.archive.ubuntu.com quantal-backports/restricted Translation-en_US
Ign http://no.archive.ubuntu.com quantal-backports/universe Translation-en_US
E: Sub-process returned an error code
Is there any usual causes for this error? Or how can i check what causes the error?

/var/log/apt/. I have no clue about the error. Try clearing your apt cache (/var/cache/apt) folder. – Capt.Nemo Oct 27 '12 at 15:45