I just upgraded from 11.04 to 11.10, and I noticed that applications can no longer request su privileges graphically. This turns out to be because the policykit agent, fingerprint-polkit-agent, isn't running. If I execute
in a terminal, then everything works as normal thereafter. But I can't work out why this isn't being executed on login. There is a file /etc/xdg/autostart/fingerprint-polkit-agent.desktop, which has the following entry:
Name=PolicyKit Authentication Agent with Fingerprint Authentication
Comment=PolicyKit Authentication Agent with Fingerprint Authentication
I also tried copying this file to ~/.config/autostart, but it still doesn't run on login.
For some reason, this problem only happens in the unity shell: if I log in with the gnome-shell interface, it works. I tried adding "Unity;" after the OnlyShowIn line, but this makes no difference.