Regarding this issue of status change on purchase order which affects the qty ordered and and qty in stock, i would like to point out if the PO is cancelled or deleted the qty ordered still remains the same, when are you looking to resolve this bug, also once the puchase order is created and thereafter qty adjusted this also does not reflect in qty ordered.

it seem you have resolved the issue of a status change from created/approved to delivered this converts the qty ordered to qty in stock, however it would be great if you can fix the above small problem which would make life a lot more simple especially when you have 5-6 people amending purchase orders etc.