Bug#479817: Bug#569035 refers to the same problem.

[Alex]

Thank you for answering so quickly. After spending a a lot of time on 
getting to know policykit, I can see that gksu or su-to-root is 
(fortunately) not needed anymore.

But my debian system still doesn't allow me or any other regular user to 
use the gnome-system-tools, even though policykit seems to be in place.

Since
	Bug #569035: /usr/bin/time-admin: time-admin: not allowed to access
refers to the same problem, I will amend my error report to that bug number.

Thank You
Alex