I changed software & update settings which may be the problem, what does the default for this look like?
I tried sudo apt-get clean,sudo apt-get update,sudo apt-get upgrade.
I also tried software-properties-gtk in terminal and it gave me:
gpg: /tmp/tmp<somerandom>/trustdb.gpg: trustdb created.
sudo apt-get update? – Alaa Ali Jun 05 '13 at 21:15