Problems with sorting

Hi

I'm evaluating the Grid widget and is very impressed so far. However I'm having a hard time getting things to work after sorting. For example a
a function like this works as expected before sorting, but will not work after a sort.

function deleteRow() {
var selected = grid.getProperty("selection/index");
deletedRow = myData.splice(selected, 1);
update();
}

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Error: 'myData[...]' is null or not an object.
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I have tried Sudhaker's examples as well and the problem is the same:
http://thej2ee.com/awdemo/examples/myexamples/add_edit_delete_rows.html

Does anyone have a solution for this?

/Best regards