We've found out that loading a page embedding Flowchart.NET from the Internet zone fails with the default Intenet permission set. That happens because of the recently added HandleArrowKeys property, whose implementation required overriding "Control.IsInputKey". Handling IsInputKey is probably considered a security risk because it can be used to steal the keyboard focus. As a consequence, HandleArrowKeys will be removed from version 4.0.2 of the control. If anyone needs to handle the arrow keys, use this method:

1) create a new class that inherits FlowChart.
2) override the IsInputKey like this:

protected override bool IsInputKey(Keys keyData)
{
  switch (keyData)
  {
    case Keys.Up:
    case Keys.Down:
    case Keys.Left:
    case Keys.Right:
	return true;
    default:
	return base.IsInputKey(keyData);
  }
}