12/04/10 14:09:33.70
なんでupdateじゃなくてrepaintなの？
あと URLﾘﾝｸ(qt-project.org) の
> Generally, you should refrain from calling update() or repaint() inside a paintEvent().
> For example, calling update() or repaint() on children inside a paintevent()
> results in undefined behavior; the child may or may not get a paint event.
は関係あるのだろうか