Watch the episode, 'Brother, can you spare two dimes'.

You know when Bart and Lisa are doing the 'Lounge room Olympics' and Bart breaks the chair doing 'Couch Pole Vaulting' and destroys the couch. It is wrecked for ever.

Then at the end of the film, with no explanation, the chair is magically fixed and is exactly in the same condition, size, shape and colour as the old one!