Sadly, I have experienced the same thing with mine.
I drive mine pretty hard because, well, it's a laptop. And my 20 month old daughter pokes at it - maybe that is my problem.
My biggest beef is the power cord. I am on my second one ($100 or so) and it is cracked with electrical tape all over it (fire threat) and barely works. I have to keep one hand on it half the time. Lame. They brag about the magnetics, but I think it isn't durable enough. Next beef is the battery - they go to crap pretty quickly. I think this is just laptop batteries in general though.
Anyway, in general I love OS X. It is the only thing to have your family on. I just think there is some room for improvement around durability. How sweet would a ruggedized Powerbook be? Maybe they have those somewhere.
Annyway . . .