Group purchase orders by period


I have a question. I have two purchase orders of the same item and vendor.

If I have in Master Planning parameters form → Standard Update Tab Firming Fields, Group by vendor check box activated and Group by period on “Week”, when I firm two orders separated by less than a week it becomes just one confirmed order. If I specify Group by period on “Month” it also groups them. (For example a date of 7/9 and 10/9 (dd/mm format)). This works well as far as I can tell.

But, if the two orders are for a date of 7/9 and 14/9, obviously if the Group by period is on “Week” it doesn’t group them, but if that option is on “Month” it doesn’t group them either. I can’t understand it. Any ideas or help?

Thank you.

P.D.: I’m using AX 2009

I would suggest looking at the hotfixes, month is by month - assuming the dates you are giving are delivery dates and not order dates.