When creating a demo dialog by code (not coded beautifully) and starting it, it has very 'strangely painted' controls (http://www.guigarage.com/?attachment_id=766). After causing a repaint, everything looks fine again. (http://www.guigarage.com/?attachment_id=767)
In the dialog, it especially concerns buttons and radiobuttons. Also apllied effects (e.g. dropShadow) show up after the repaint.