The package is still in the Proposed repository. Meaning, that if you don't have the proposed repository activated you can not install these packages. To activate the proposed repository you can either use the GUI or the command line:
Command Line
Manual addition
With root permissions edit your /etc/apt/sources.list
:
sudo vim /etc/apt/sources.list
Then look for the following line or add it yourself:
deb http://archive.ubuntu.com/ubuntu/ precise-proposed restricted main multiverse universe
(If you are not using precise, you can replace it with your current version)
Save your file. Then run sudo apt-get update
and install the package you want to use sudo apt-get install package/precise-proposed
or sudo apt-get -t precise-proposed install package
.
One liners
sudo sh -c "echo 'deb http://archive.ubuntu.com/ubuntu/ $(lsb_release -cs)-proposed restricted main multiverse universe'" >> /etc/apt/sources.list
sudo apt-get update
sudo apt-get -t precise-proposed install adobe-flash-properties-gtk
Done.
From the wiki page on the -proposed repository:
To enable the proposed archive for Ubuntu 11.04 go to Applications→Ubuntu Software Center→Edit→Software Sources→Updates and ensure that natty-proposed is ticked.


Update your cache, and install the desired package.
/etc/apt/sources.list.d/canonical_partner.list' – dedunu Sep 07 '13 at 05:00