Stock allocation not happening in Make to stock process

Hi,

When i created a sales order for a material 1724,the ordered quantity is 5,but the confirmed qty is 3.So i did partial delivery for 3 qty.Latter on through movement type 561 i increased the qty to 5.Now stock of 5 qty is available.I am planning to do delivery for pending qty in already created sales order.

When i did delivery,system indicated Order cannot delivered "No schedule line",i Changed the delivery dates also but i cannot make out.

Also ready the below thread,tried to do delivery,but it was not possible for me.

Make to Stock - Sales order stock allocation | SCN

Please help me do delivery for remaining material.

The screen shots are attached.

Note:There is no other pending orders ,delivery apart from this.