The appearance of a group box changes automatically to conform to the current display setting. When the display is set to the Windows XP Theme, the group box rectangle appears with rounded corners and a single-line border. When the display is set to the Windows Classic Theme, the group box appears with square corners and a shaded double-line border.
If you set this attribute after the widget is realized, its affect is immediate (if the widget is visible).
When TRUE, the ROUNDED attribute setting is ignored.
