Not able to change sales order in the "Component Overview" of CO08

Hi all,

While creating a Production Order based on a Sales order in CO08, in the "Component Overview" enter the component material and quantity, operation, plant... press Enter, the sales order and item get automatically appeared and are not changable.

This is happening after my system upgrade from R3 to ECC, in R3 I was able to change that fields.

can anyone tell me if this is a standard behavior of ECC?

Thanks

Danny