Po issue

Hi

I have created for purchase requisition one material for 2200 qty,then i completed purchase order for 258 qty, Purchase Order Unit of Measure is bag,so my system takes 258*4=1032 as a ordered quantity,now balance open quantity 1168 is available in my purchase requisition item quantity/dates tab also showing,

Then i start to create another po with refernce to purchase requisition number that time my system takes qty 1168,same material,plant automaticaly, but system showing error Articles/services for requisition 10001550 00100 already ordered with 1,032 EA

Message no. 06400

In my purchase requisition closed radio button also not active,

Regards

Mani