CRITICAL bug in acquisition (another one...) : when MARC=ON, and an order line is...

CRITICAL bug in acquisition (another one...) : when MARC=ON, and an order line is created from an existing biblio (to buy another item), the MARC biblio is lost and replaced by the non marc one (that has a lot less informations...). To solve the problem, the biblio can no more be modified after the order has been placed. Less feature, but more reliable ! (not simple solution to solve this problem. Would imply to rewrite the MARC biblio from the non marc datas, and no API is provided for this yet)