Comment 6 for bug 976638

Maybe I'm posting in the wrong place, if so, thank you for telling it and guide me to the wright one. I have also a problem with synaptic and polkit when I launch it from the menu with synaptic-pkexec it gives me this error (seens Xubuntu 11.10):

(polkit-gnome-authentication-agent-1:8248): polkit-gnome-1-WARNING **: Unable to get a pixbuf for GTK_STOCK_DIALOG_AUTHENTICATION (gtk-dialog-authentication) at size 48

I'm on Xubuntu 12.04 LTS 64 bit and by every session (autologin + autostartx with mingetty and no DM) I got this error from polkit-agent:

(polkit-gnome-authentication-agent-1:8248): GLib-CRITICAL **: g_variant_new_string: assertion `string != NULL' failed

(polkit-gnome-authentication-agent-1:8248): polkit-gnome-1-WARNING **: Failed to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files

The workaround is to start synaptic in a terminal with gksudo synaptic and no error occur.