I have updated dokuwiki and the arctic template to the latest release. But now the main sidebar is not showing on non-toplevel namespaces. Before I updated it worked perfectly (dokuwiki version 2008-05-05).
Example:
Here the sidebar is showing
http://www.greenbird.info/
http://www.greenbird.info/attic
Here it disappeared
http://www.greenbird.info/electronics/small_projects/flashing_led