my macbook won't start up.

hey guys im on the boot camp partiotion of my macbook right now, but whenever i try to startup normally (with the leopard OS) i hear the chime like normal, the apple and the swirling gear comes up (like normal), but then it goes to this blue screen with the swirling loading gear and it just stays on there. i left it for an hour and still nothing. I reset the PRAM, tried to boot in safe mode but the didn't work. I need some serious help, all of my files are on my mac half of my macbook.

Help guys.