I have a hard one here.
I can reproduce this behavior only with Delphi 7.
You need a frame with TsFrameAdapter on it.
Drop a TsPanel in the frame.
Drop a TsRadioButton in the panel at the very top of it (Top=0).
Set the visible property of the radiobutton to false.
In a TForm, drop a TsSkinManager and select a skin.
Drop the frame on the form.
Run the application.
The radio button is not visible, but if you mouse over where it would be from the top, it shows suddenly.
It does not shows if the mouse comes from the bottom.
It is like, if the first thing under the mouse while entering the panel is the radio button, it makes it visible.
Stephane Senecal
CIS Group
Delphi programmer since 2001