Flex Advanced Data Grid collapses on refresh

I was having this problem with my Advanced Data Grid. Every time the data refreshed the whole thing collapsed, which isn't a good thing when users have drilled down 3 levels.

I know this is probably a bad way of doing this, but it is the only way I could get to work. All the examples I've seen of this say to just assign the saved openNodes Object to the openNodes property, like this...

myOpenNodes = new Object();
myOpenNodes = IHierarchicalCollectionView(myADG.dataProvider).openNodes

//refresh here

IHierarchicalCollectionView(myADG.dataProvider).openNodes = myOpenNodes;

but that doesn't work!!

Here is what I did:

On the refresh method set the following variables (these variables need to be accessible from all methods inside the component, so put them in your model or make them global, whatever). These variables hold the state of the ADG before the refresh.

//Object holding all currently open nodes
myOpenNodes = new Object();
myOpenNodes = IHierarchicalCollectionView(myADG.dataProvider).openNodes

lastSelectedItem = myADG.selectedItem;

lastScrollPosition = myADG.verticalScrollPosition;

This method loops through every item in the advanced data grid up to the depth you provide (here it is to the depth of 4). Then any time it finds an object that is also in the myOpenNodes object it adds to to an array that then is assigned to the ADG.openNodes property. In this example the property of the grid item I am using to compare is called "Group".

private function selectLastADGItem(evt:Event):void
{
   //Array to assign to openNodes property
   var savedNodesArray:Array = [];
      
   for(var i:int=1; i<4; i++)
   {
      var dataCursor:IHierarchicalCollectionViewCursor = myADG.dataProvider.createCursor();
      
      while (dataCursor.current)
      {
      
  for each ( var item:Object in myOpenNodes )
  {
     //Check if current item is in openNodes object
            if ( item.Group == dataCursor.current.Group )
     {
        savedNodesArray.push(dataCursor.current);
     }
     
            //Check if current item is the last selected item
            if ( item.Group == dataCursor.current.Group )
     {
        myADG.selectedItem = dataCursor.current;
     }
  }
       
  dataCursor.moveNext();
      }

      myADG.validateNow();

      //Assign new array to openNodes property                    IHierarchicalCollectionView(myADG.dataProvider).openNodes = savedNodesArray;
     
      myADG.dataProvider.refresh();
   }
    
   //Move vertical scrollbar to last position
   myADG.verticalScrollPosition = lastScrollPosition;

}