Setting x & y on ToolTip.Show somehow sets duration as well?

When I call ToolTip.Show() like below;

ToolTip.Show(Message,MyControl);

Everything works perfectly, it shows and goes away when MyControl looses focus. However the position of the ToolTip is over MyControl so I want to add an offset;

ToolTip.Show(Message,MyControl,10,-20);

The ToolTip does position the way I want, it shows when hovering over, but is does not disappear anymore on MyControl loosing focus. The behaviour is similar to setting the duration very high.

When I look at the ToolTip.Show() definition, one of the ways to call it is like this;

public void Show(string text, IWin32Window window, int x, int y);

So how can the ToolTip suddenly stop disappearing when I only add the x & y offset and not touch the duration?