Why book re-ordering is not being saved?
It's an old bug when you have too many pages, I've been struggling and finally still doing it through MySQL :

it's 'menu_links' table and Weight value in DB , and flush cache well

it's from my old question How to reorder Book module menu through Database?


Hello, who deleted My Answer?! - This IS ANSWER not Bug report, indeed! You can use my answer about MYSQL data tables! Why joke and delete?!