My update manager does not find any updates. It does not crash or anything, but no update for my ubuntu, except for the PPAs. At first I thought there really was no update out there, but now it has been more than a month since my last update. What is wrong here?
$ cat /etc/apt/sources.list deb http://ir.archive.ubuntu.com/ubuntu/ precise main restricted universe multiverse
(I also tried the MainServers, but still nothing.)