Disable annoying auto save?

Add to wp-config.php

define(‘AUTOSAVE_INTERVAL’, 160 ); // seconds

Edit this to the seconds desired

http://codex.wordpress.org/Editing_wp-config.php#Modify_AutoSave_Interval

Or add to functions.php preferably in a Child Theme so the edit is not lost on theme update:

function disableAutoSave(){
    wp_deregister_script('autosave');
}
add_action( 'wp_print_scripts', 'disableAutoSave' );

Source: http://www.wprecipes.com/wordpress-hook-disable-posts-auto-saving

I provided the codex article on this – your theme can override – try with a function.