I just installed the latest version of Linux Mint 14 “Nadia” KDE but the update manager is still broken. It shows the shield and indicates updates needed but when you click on it then it asks you for your password but after filling it in then pressing enter it crashes and then disappears. No matter how many times you reload it still hides or disappears. I was following this forum and Sunno posted:Open terminal and type: sudo apt-get update && sudo apt-get upgrade ( this does apparently the same thing that the update-manager does)..... But keep in mind updating the packages via command line sudo apt-get update && sudo apt-get upgrade may cause the network connection to drop (my connection is hardwired RJ45 but it still froze the connection). Next the computer will need a hard restart it is unreponsive time suspended and no mouse actions. After the hard restart go enter sudo apt-get update && sudo apt-get upgrade again in the terminal and it should finally update without dropping the network connection again.
On every change I press Y ( among other things :the update-manager_4.4.4 is then installed)
After this is done, it is displayed that some packages are not installed, there are being hold back. (These packages seem to be essential, because the new update-manager_4.4.4 doesn't work without them.) Open Synaptic Package Manager and click in the left down corner on 'Status' then in the left upper corner 'installed( upgraded)' and install them all. Update Manager 4.4.4. should work now without any problem.
I will say this is correct after upgrading 2 packages in the update manager in the left down corner on 'Status' then in the left upper corner 'installed( upgraded)' and install them then the update manager starts to work again.
This is what worked for me.