DataGrid not rendering images during scrolling

Question

I've created a "Reusable Inline Item Renderer" to display an
image in a DataGrid's column, as is shown here:
http://www.adobe.com/devnet/flex/quickstart/using_item_renderers/#reusable_item
With one difference: In the example the source of the Image
component in the item rendered is being set to the URL of an image
file. In mine I am setting the source as a Bitmap object, the
Bitmap being a public and Bindable property of an Object in an
Array. This Array of Objects is the DataGrid's dataProvider.
And it works fine, except that when I scroll the DataGrid,
any images that have been scroll off screen and then back on again
are blank where the image used to be. I've tried tracing out the
source of each Image when it renders and it still has a Bitmap
object as it's source even though it is no longer displaying
it.

Answer 1

I have been beating my head against the wall on this problem too for awhile now.  There is precious little mentioned anywhere about it.
I tried to recreate your code, as follows, to solve my problem but now am getting compilation errors.
Can you please share your code segment on how you did it?    (It would also be helpful to see how you call it too.)  I am loading images from the web with Loader.
This does not compile:
        public function get data():BitmapData {
            return _data;
        public function set data(value:BitmapData):void {
            _data = value;
             var newBitmap:Bitmap = new Bitmap(value);
            source = newBitmap;
In my main class, the data provider is already populated, so I am replacing the cell with the bitmap.
Thanks for any help you can give.