Ok.. this is downright disturbing.

Accoridng to Gamespot:

What we heard: According to dozens of forum posts and lower-end game sites, many of the first batch of PSPs suffered from a variety of defects, including “dead pixels, dead drives, analog sticks not working and even falling off, and even screens with dust and ‘air bubbles’,” according to Engadget. A more spectacular alleged problem was the so-called “Master of the Flying UMD Guillotine Trick.” According to reports–one of which even featured video evidence–if you twist the PSP a certain way, the UMD drive opens, causing the disc to come flying out like a throwing star. Luckily, GameSpot can address both these rumors head on. While in Japan last weekend, GameSpot editors did observe some PSPs with dead pixels, but did not see any evidence of the other defects. As to the flying-disc glitch, we were brave enough to use one of our precious PSP units to test the theory. Amazingly, with just the right touch, out it popped.