I have a system where I have the development version 13.04 that is not checking for updates.
From the command line "sudo apt-get update" completes without any error, and "sudo-apt-get upgrade" afterwards installs all the available updates without error. In system parameters "check updates daily" is marked, but the system refuses to do it, if I don't issue the "update" command manually no updates are offered.
I'm behind a proxy that is working perfectly otherwise. I have checked /etc/environment and /etc/apt/apt.conf and I can see the proxy correctly defined in these two places, and in any case as I said "sudo apt-get update" finds the repositories that I use without any error.
What can be preventing my system to check updates automatically?