If you, like me, got that really annoying message from update manager regarding failed download of additional data ( usually flashplugin-installer in my case) every time you login, I just found the answer at ubuntu forums .
1 2 3 4 5 6 7 | root@saturn:/var/lib/update-notifier/user.d# pwd/var/lib/update-notifier/user.droot@saturn:/var/lib/update-notifier/user.d# ls -l | grep failed-rw-r--r-- 1 root root 24155 Dec 17 10:33 data-downloads-failed-rw-r--r-- 1 root root 27963 Feb 15 08:16 data-downloads-failed-permanentlyroot@saturn:/var/lib/update-notifier/user.d# rm data-downloads-failed*root@saturn:/var/lib/update-notifier/user.d# |