Because the cracks are appearing most often in the bottom corner(s), I'm thinking it may have to do with how tightly the Kindle is held while reading. There would be a tendency to put more pressure in that area, since the page-advance buttons are right there. And it's a natural place to grasp to balance the device too. This may be something to pay attention to, but this cracking shouldn't be happening, of course!
This doesn't really explain why some Kindles may arrive from the factory with this defect. I'm wondering if cold weather during shipment may be making the plastic more fragile and easier to crack?
I have the Amazon cover, and I usually hold it by cradling the cover itself, being careful not to grasp the device itself too tightly. It does help that I read while propped up in bed, so I don't really need to grip the device itself to hold it in place. If you read while in a supine position, that may be more challenging.
Last edited by DreamWriter; 01-21-2011 at 02:53 PM.