1054 - Unknown column 's.public_flag' in 'where clause'
select count(*) as total from orders o, orders_status s where o.customers_id = '2' and o.orders_status = s.orders_status_id and s.language_id = '1' and s.public_flag = '1'
[TEP STOP]

This problem is caused by a missing database entry, to resolve it all you have to do is edit the database with phpmyadmin and add the following

alter table orders_status add public_flag int DEFAULT '1';

It will add the missing column.