The maximize on Mac OS X works, then concept is different from Windows. Maximize does not necessarily mean "fill the whole screen with one window" under OS X, but that doesn't mean it is broken. Play around with Preview to get it.
I've played with it. Apparently the algorithm is, "generate one random number and set the window height to that, generate a second random number and set the width to that".
Ok, than you don't get it. I've decided to make a mini-tutorial about this. I will update at this place when it's ready. Stay tuned (if you want).