When you've started the DVD and you get to the title menu you see a desk with a phone on it, and the usual play, scene select etc options. If you wait for a few minutes until you hear the phone ring, then select play, you are taken to an extended version...
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On the second disc choose the extended scene of David reading, and press up+x 6-7 times in a row, and the light will go off and the film will show.I say that this requires a PS2 because I discovered this with a PS2.