I have installed latest version of KDE, so I have to use the workaround post here
Install bzr via Synaptic Package Manager
$ bzr get lp:~ubuntu-core-dev/update-manager/maverick
$ cd maverick/DistUpgrade $ sudo ./dist-upgrade.py
I saw a warning message on screen
WARNING: Failed to read mirror file
Several minutes later, another error
"Error authenticating some packages"
There is a bug748353 for this.
Btw, I have to create a file /etc/apt/apt.conf to work behind proxy.
Follow up:
switch to gnome, uninstall kubuntu-desktop, and upgrade via "update-manager", now the upgrade is in progress.
