Flex AdvancedDataGrid c/p rows issue - actionscript-3

Question

I'm a newbie in Flex/AS3 development and I came across an issue that bugs me for a while now. I'm using an AdvancedDataGrid with some columns, and an ArrayCollection as the provider. I would like to make a copy/paste functionality so that multiple rows can be selected, copied, and then pasted below the selected (or last selected row).
The problem is when I copy the data from one row to another, both of those rows become highlighted on mouse-over (upper instance isn't even selectable) - just as in this topic: Flex DataGrid/DataProvider bug?
First I thought it was the issue of copying the reference, but it persist even if I use ObjectUtil.copy() method. Furthermore, I manually change one of the properties called "order" so that the objects of the ArrayCollection aren't identical, but it doesn't help. Dataprovider is called newTreatmentData, and the DataGrid is newTreatmentDG.
Any suggestions are more then welcome.
Here's part of the code that is relevant:
private function getSelectedRow(event:Event):void
{
selectedRow = newTreatmentDG.selectedIndex;
}
private function copySelection(event:Event):void
{
bufferData = new ArrayCollection();
var sortedIndices:Array = newTreatmentDG.selectedIndices.sort();
for (var i:int = 0; i < newTreatmentDG.selectedIndices.length; i++){ //copy selected rows to the buffer
var j:int = sortedIndices[i];
bufferData.addItem(newTreatmentData[j]);
}
}
private function pasteSelection(event:Event):void
{
var rowsToMove:int = newTreatmentData.length - selectedRow - 1; //number of rows to move after pasting
for (var i:int = 1; i <= bufferData.length; i++){
if (selectedRow + bufferData.length + i > newTreatmentData.length){ // adding objects to the array collection to avoid range error
newTreatmentData.addItem(null);
}
}
for (i = 1; i <= rowsToMove; i++){
newTreatmentData[selectedRow + bufferData.length + i] = ObjectUtil.copy(newTreatmentData[selectedRow + i]) //first move the rows to "give room" for pasting
newTreatmentData[selectedRow + bufferData.length + i].order = selectedRow + bufferData.length + i; //manually changing the "order" property, but it doesn't help
}
for (var j:int = 1; j <= bufferData.length; j++){ //paste the data from the buffer
newTreatmentData[selectedRow + j] = ObjectUtil.copy(bufferData[j-1])
newTreatmentData[selectedRow + j].order = selectedRow + j; //again changing the order property
}
newTreatmentData.refresh();
}

Answer 1

I solved it by changing the mx_internal_uid property of every object in the dataprovider ArrayCollection. It seems that AdvancedDataGrid checks it to see if rows are equal. I assumed (and you know what they say about assumptions) that an object's UID changes when you copy its value into another object (hence the U in UID ;) ).