The cracking case can occur on the top or the bottom of the interior casing. It’s caused by closing the top of the computer too quickly; repeated attempts will start cracking the case slowly, on top or bottom… or both.
When this started happening, numerous complaints were made about lesser quality and poor craftsmanship to be held responsible, and maybe that was the case. However, after copious amounts of people started coming in to get the repair made (for free if they were still under their limited warranty, or had purchase the AppleCare protection plan), they issued a statement telling all MacBook customers, that they were eligible for the replacement, regardless of their warranty or AppleCare status.

Old White MacBook Top Case Cracking
This was wildly accepted, as you could imagine, and was a quick and timely repair, should you be close to an Apple retail store. The repair involved replacing the entire top case (this means new keyboard, new casing, new power button) which is essentially a facelift for your Mac. When I got my machine back from the store, it looked like it was brand new, a nice surprise and something that I greatly appreciated.
If you currently have a cracking case on your white MacBook, head to the nearest Apple retail store (after making an appointment), or your nearest Apple authorized service centre, to get this manufacturer defect taken care of. Make sure that the service provider you lookup, supports service; some of them are iPod only, Mac only, etc… make sure you choose the right one, and be sure to call before you drop in for a visit!

Old White MacBook
In case you’re having trouble identifying your machine, look on the bottom right – if you have a black circle like the image displayed above, and your case is cracking, you’re in luck – you’re eligible.

