>Hi everybody,
>
>I noticed a strange visual effect for the checkbox which is placed on a pageframe. When the checkbox is focused, its font seems to become bold.
>When I click somewhere on the form, the font goes back to normal.
>
>Do you know what may cause this visual effect and is there a way to remove it?

I've done that on purpose for my base checkbox class (by turning bold on/off in .gotfocus/.lostfocus), because there's very little other visual cues that a checkbox has the focus. The outline is too thin, doesn't look good and generally can't be spotted (and may be completely absent, depending on theme and whatnot).