Auto Fulfill Drop Ship POs

I want to autofulfill drop ship POs...  I thought I had it working, but somehow the fulfillment items are not tied to the PO.  It works correctly if I create the fulfillment in the UI, but using nlapiTransformRecord, it fulfills from our stock, creating negative quantities.

Do I need to manually set that it is a drop shop PO?  The UI does this automatically.

Here's the Code that gets run on a Drop Ship PO Save Record Function:

 function dropShipSaveRecord() {    var id=nlapiGetFieldValue('createdfrom');   if(id) {    var items=new Array();    for(var i=1;i<= nlapiGetLineItemCount('item');i++) {     items[nlapiGetLineItemValue('item','item',i)]=nlapiGetLineItemValue('item','quantity',i);    }       var fulfillRecord = nlapiTransformRecord('salesorder', id, 'itemfulfillment');    fulfillRecord.setFieldValue('generateintegratedshipperlabel','F');    for(var i=1;i<= fulfillRecord.getLineItemCount('item');i++) {     var itemid=fulfillRecord.getLineItemValue('item','item',i);     if(items[itemid]) {      fulfillRecord.setLineItemValue('item','itemreceive',i,'T');      fulfillRecord.setLineItemValue('item','quantity',i,items[itemid]);     } else {      fulfillRecord.setLineItemValue('item','itemreceive',i,'F');     }    }    try{     nlapiSubmitRecord( fulfillRecord );     } catch(e) {         var errorTxt='Error creating fulfillment: '+e.code+': '+e.message;        alert(errorTxt);      }   }      return true;   }