Setting Lot Number on Item Receipt

Please tell me this has been done ... and I've not run into a SS2 Bug.  Its very simple, I'm fully receiving a PO and need to add the Lot Number to the line.

 var itemReceipt = record.transform({fromType: 'purchaseorder', fromId: 1, toType: record.Type.ITEM_RECEIPT, isDynamic: true});    itemReceipt.selectLine({ sublistId: 'item', line: 0 });  itemReceipt.setCurrentSublistValue({ sublistId: 'item', fieldId: 'itemreceive', value: true });  itemReceipt.setCurrentSublistValue({ sublistId: 'item', fieldId: 'quantity', value: '5' });    var inventoryDetail = itemReceipt.getCurrentSublistSubrecord({ sublistId: 'item', fieldId: 'inventorydetail' });  inventoryDetail.selectNewLine({ sublistId: 'inventoryassignment' });  inventoryDetail.setCurrentSublistValue({ sublistId: 'inventoryassignment', fieldId: 'receiptinventorynumber', value: 'FAKE_LOT' });  inventoryDetail.setCurrentSublistValue({ sublistId: 'inventoryassignment', fieldId: 'quantity', value: '5' });  inventoryDetail.commitLine({ sublistId: 'inventoryassignment' });    itemReceipt.commitLine({ sublistId: 'item' });    itemReceipt.save();