Comment 23 for bug 499937

Excuse me if I wrote this in another duplicated, and any mistakes I'm not English native speaker, but maybe this give to you more clues about the problem.

Maybe the problem in bigger than that, because I have the same problem after reinstall pulseaudio (because headphones don't mute speakers and right now I have the problem and more) startup applications doesn't work (specially nm-applet --sm-disable is the most important, maybe the policy kit too as you point here), Installation by Ubuntu software center the same problem than here, In Ubuntu tweak I cannot unlock anything and some administratives task I cannot do since pulse audio uninstall. For instance, I cannot change my own user privileges or activate propietary drivers and my folders (Documents, Downloads, Public, etc) in the left panel of Nautilis dissapear and cannot put them in its original place on Nautilus, among others task and weird things. Take in account that my user is a sudoer and all this stuff worked before. Another friend had the same problem and follow the steps to update pulse audio and the same or when another users unistall some system-wide applications.

I tried removing completely (even home directory) and recreate my user from another sudoer and again the same problems. But if I create a new administrator user, it have everything correct, something in another place that have a record for users permissions or something is the problem and when the user is eliminated don't eliminate its information, because even re-creating the problematic user cannot recover its original situation.

this is the output in my laptop when launch the policy kits

myuser@ubuntu:~$ /usr/lib/kde4/libexec/polkit-kde-authentication-agent-1
New PolkitAgentListener 0x11e44e0
Adding new listener PolkitQt1::Agent::Listener(0x11fd5c0) for 0x11e44e0

(<unknown>:6692): GLib-GObject-WARNING **: cannot register existing type `_PolkitError'

(<unknown>:6692): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed

Someone said that a workaround is launching Gnome policy kit and this is the output and I'm not sure if it wasn't launched on startup process as the kde version. Both was on statup applications but launched by the user not as root (via sudo).

myuser@ubuntu:~$ /usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1
(polkit-gnome-authentication-agent-1:6784): GLib-GObject-WARNING **: cannot register existing type `_PolkitError'

(polkit-gnome-authentication-agent-1:6784): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed

** (polkit-gnome-authentication-agent-1:6784): WARNING **: Unable to register authentication agent: Remote Exception invoking org.freedesktop.PolicyKit1.Authority.RegisterAuthenticationAgent() on /org/freedesktop/PolicyKit1/Authority at name org.freedesktop.PolicyKit1: org.freedesktop.PolicyKit1.Error.Failed: An authentication agent already exists for session
Cannot register authentication agent: Remote Exception invoking org.freedesktop.PolicyKit1.Authority.RegisterAuthenticationAgent() on /org/freedesktop/PolicyKit1/Authority at name org.freedesktop.PolicyKit1: org.freedesktop.PolicyKit1.Error.Failed: An authentication agent already exists for session

I expect that this give you some clues about this problem or still better maybe exists a solution from another problem described here.

If you need more information or something don't hesitate and excuse me for my lack of experience in this matter or if this is noise in the thread.