If a font is selected in the FontName dropdown and then some code is pasted in the editor's content area (font stripping is turned on) then the selected font is cleared and did not applied to the pasted content. What the user is trying to do is to have it paste into the font that he has selected in the rad editor not into the default font of the browser nor the default font of the rad editor.
The research shows that this is a browser behavior that cannot be disabled.