MacBook Pro won't boot (question mark folder) after blue screen on windows bootcamp

Hi,

So, I was on windows, using bootcamp, and I was creating partitions on a pen drive with it, and then it asks me that it needs to restart to apply changes.

But then, while restarting, a blue screen occurred (**** windows).... And I forced the shutdown pressing the power key.

Then, I simply turned the MacBook on, trying to boot on my snow leopard and I got a flashing folder with a question mark on it.

Now I can't access any partitions on it, if I press option key on startup I get a blank window!

I tried to reset PRAM, repair the MacOs partition using the snow leopard DVD (it shows up fine, along with windows partition and EFI partition), and I still don't get my startup disk showing up...

How can I fix this? I can't loose my files and I need to work with it :/