Aloha,

as per the discussion on the list, here's a patch that enables you to turn off
sorting again by officially blessing the magical sort column value that denotes
an unsorted store and by removing/adjusting some assertions.

Also attached are two sample applications.  When you click on a column heading,
the sorting mode changes to ascending, descending or none, depending on the
current mode.  Activating a row adds a new row, to test/demonstrate whether new
rows get sorted correctly.

Bye,
-Torsten