Menu Order Problem
For some of our Joomla 2.5 sites, the menu order changed by itself (possibly after a secuity update). We started seeing this problem around Nov 2013, particularly with sites that were upgraded from Joomla 1.5
Cause:
Joomla 2.5.16 gets confused when the "order" record is filled out in the "_menu" table in the Joomla database.
Solution:
To fix required knowledge of SQL. You will need to edit the joomla database manually using phpMyAdmin, or SSH in and use SQL.
We need make the "order" record = 0 for every menu item. This is the SQL command to execute...
UPDATE `joomla_database`.`prefix_menu` SET `ordering` = '0'
Where 'joomla_database' is the joomla database name, and 'prefix_menu' is your joomla _menu table name. These names are different depening on your installation.