Chips, chips everywhere, but not a single one to eat!

Joystiq reader 'MUhockey' has sent us his crazy experience of trying to buy a PSP, only to find that he had to return the thing five times due to the screen being damaged either by dead pixels or chips in the screen. It's possible that this was merely a batch that got a bit of rough treatment in the mail to Wal-Mart. On the other hand, it's hard to see how a PSP which was in its package could be damaged in such a way as to cause chips in the plastic. Any ballistics experts want to help us out with explaining the required forces to chip a PSP screen?

Here's what 'MUhockey' had to say;

"I recieved a PSP for my birthday and I found dead pixels in it, nothing new right? Well I took it back to Wal-Mart and they let me check out the next one I was getting so that I could make sure it worked okay. Well this one had a small chip in the screen. So we looked at another, and another, and another. In the end, I took ten new Sony PSP's out of their boxes and found very tiny chips or blemishes in the screens. Not real sure if anyone else has found this trend, but it has postponed my purchase of a PSP."

So there you go. Has anyone else had any problems with 'chipped' PSPs (the physically damaged kind, not the pirated kind) coming out of the box?