Black border on button gives impression that button is focused

Hi,

When making a panel visibile I set a SaveButton in the panel as default button so I can click it with enter. I also use SaveButton.Focus(). When I start typing my input in a textbox in the panel the focus goes away from the SaveButton, naturally, but instead a TopButton on top of the page outside this panel gets a thin black border around itself, (not the dashed rectangle used to show focus), but enough to give an impression that this TopButton now is focused in someway. How can I get rid of that border thing and preferrably put it around the SaveButton instead?
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