hmmmm, doing network system update will update you to the latest 5.1.1 and we don't want that.
The only next thing I can think of would be to find a game that has a required system update on the disc lower then 5.1.1
Can't we have auto update or auto download updates turned off but have stand by turned on? For use of the quick start menu without fear of an auto update? I can quite remember all the options in the setting menus.