I'm very sorry for delays with answer,
This incrrectness already fixed and will avaliable in the nearest update (beginning of next week), now you can use following code:
[C#]
private void UpdateDataSet()
{
int focusedRow = flyGrid.Rows.GetRowFromNode(flyGrid.Selected);
'update dataset
myDataSet.AcceptChanges();
if (focusedRow != -1)
{
NodeBase node = null;
try
{
node = flyGrid.Rows.GetNoeFromRow(focusedRow);
}
catch
{
//focusedRow can be more greater than current row count
}
if (node != null)
flyGrid.Selected = node;
}
}