That's an insane failure rate.
What's the DSlite "crack" that was mentioned?
I'm pretty sure that it would do some damage if you left it for too long, I got mine replaced and so far the newer one doesn't have the crack.....or meth.
I've had my crack for a whiiile, and its survived two serious drops, which yielded cracks in my poor DSlite enamel. I game hard.