r14213 - gnucash/trunk/src/gnome-utils - The description for the "sort_column" gconf key of the tree_views says,

[Chris Shoemaker]

Author: chris
Date: 2006-05-27 22:23:37 -0400 (Sat, 27 May 2006)
New Revision: 14213
Trac: http://svn.gnucash.org/trac/changeset/14213

Modified:
   gnucash/trunk/src/gnome-utils/gnc-tree-view.c
Log:
   The description for the "sort_column" gconf key of the tree_views says, 
   "Possible values for this setting are the name of any column in this 
   dialog (see the column_order key) or the keyword 'none'."

   The third click on a column header removes the sorting by that column.  
   This patch will now store 'none' for the sort_column in that case.