Making Ubuntu Software Center work with KDE Plasma Desktop

After installing the KDE Plasma Desktop on top of Ubuntu 12.10, the Ubuntu Software Center is unable to install or remove any applications. On performing these operations, the software center gives this error message - 

Authentication Error
Software can't be installed or removed because the authentication service is not available. (org.freedesktop.PolicyKit.Error.Failed: ('system-bus-name', {'name': ':1.184'}): org.debian.apt.install-or-remove-package

To fix this issue, install the PolicyKit Authentication Agent for KDE -

sudo apt-get install polkit-kde-1

You might need to logout or restart for the changes to take effect.

Reference -

• Ubuntu Software center is not working on ubuntu(With KDE desktop environment)

Adding a volume indicator to the KDE panel in Ubuntu

The volume indicator does not show up in the KDE panel after installing it on Ubuntu 12.10. Installing kmix fixes this issue -

sudo apt-get install kmix

Reference - https://answers.launchpad.net/ubuntu/+question/79037