When i went to start my MBP this morning it started completely normally until it got to the point where it goes from the gray loading screen to the blue screen right before it loads the desktop. It will not go past the blue screen. I left it like that for about 4 hours this morning and when i got back it had still not moved on. I tried reinstalling the operating system using the upgrade option, and i still does not work. I also verified the disk and permissions off of the install dvd which works fine. Both were ok. Does anyone have any ideas what could be going on.