i have a late 2009 Macbook Unibody. The thing is, it has a problem booting UP. At times, it was stuck at the loading screen (apple logo) then wont continue to boot UP. I've tried using the sbin command at terminal, resetting the PRAM, even using the utility tool to repair disk permissions but none of this wont work. Then eventually after so many tries, I manage to boot it up, but my problem is that the problem might spring up again if i shut it down and try to boot it up again. Please help. 