DECLINED: this happens only when the double click is outside the bounds of the scroll button which is the expected behavior.

To reproduce: When the user clicks too fast on the quite thin area between the grid's scroll-bar arrow button and the row, it fires the CurrentRowChanging event.

Workaround:
private bool cancelChanging = false;

private void radGridView1_CurrentRowChanging(object sender, CurrentRowChangingEventArgs e)
{
if (cancelChanging)
{
e.Cancel = true;
cancelChanging = false;
}
}

private void radGridView1_MouseDoubleClick(object sender, MouseEventArgs e)
{
cancelChanging = false;

RadElement element = this.radGridView1.Behavior.GetHoveredRadElement();

while (element != null)
{
if (element.GetType() == typeof(RadScrollBarElement))
{
cancelChanging = true;
break;
}
element = element.Parent;
}
}