I am also seeing this problem and it is very annoying. To clarify what others have said, I found that the workaround is:
$ sudo su -
$ apt-get upgrade
I found that 'sudo apt-get upgrade' doesn't work as it does not seem to pick up the http_proxy setting. Further, if I have accidentally tried to upgrade without switching to root, I have to remove the flashplugin-installer package and then reinstall it:
I am also seeing this problem and it is very annoying. To clarify what others have said, I found that the workaround is:
$ sudo su -
$ apt-get upgrade
I found that 'sudo apt-get upgrade' doesn't work as it does not seem to pick up the http_proxy setting. Further, if I have accidentally tried to upgrade without switching to root, I have to remove the flashplugin- installer package and then reinstall it:
$ sudo su - installer installer
$ apt-get remove flashplugin-
$ apt-get install flashplugin-