Comment 3 for bug 138776

What we have to do at Ubuntu is to assure that a privileged user is not only in the "admin" group (to perform commands as root using sudo) but also in the "lpadmin" group (to send administrative requests to the CUPS daemon) and perhaps also in other groups to get admin privileges on other daemons/services.

This must be assured on updates from any Ubuntu distro to Gutsy and also on fresh Gutsy installations. I have seen complaints elsewhere that the "lpadmin" membership got lost on updates to Gutsy.