'BAPI_OUTB_DELIVERY_SPLIT_DEC' after Partially picking

[Shizofrenik]

Hi, expert.
I've stuck with problem of using  'BAPI_OUTB_DELIVERY_SPLIT_DEC' after Partially picking.
I have a delivery with 4 items

I try to fill lt_itemdata table, with values, and i want just to save this picked quantity and transport the rest into new delivery.

And call FM

CALL FUNCTION 'BAPI_OUTB_DELIVERY_SPLIT_DEC'
      EXPORTING
        delivery              = vbeln
        businessprocess       = '0002'
        deliverynew           = newdelivery
        deliveryitemsbelongto = 'O'
        techncontrol          = techncontrol
      TABLES
        itemdata              = lt_itemdata
        return                = lt_return.

After executing i recieve the next : some items was saved with picking quantity, some was transport to new delivery with picking quantity.
OLD DELIVERY

NEW DELIVERY

Why it's happening?
How always to save the picking to old delivery?