The bug causes any new manual order created to jump to 2147483647 and therefore any orders after that placed by customers will get the following message on checkout -order confirmation:
1062 - Duplicate entry '2147483647' for key 1
until I remove the manual order from the PhpMyAdmin, then orders placed by customers will autoincrement as normal
I think the bug is between Order Editor and Manual Order creator contributions and relating to MySQL tables