Hello, first off let me start out with some background info, In July i ordered the new 15" macbook pro, 2.8ghz, 4gb ram, 500 gb 7200rpm hard drive. everything ran great until early september when my computer got really laggy and i kept getting the spinning beach ball so i restarted and it would not get past the grey apple loading screen. Using disk utilities it said that it could not repair the HD and there was an "invalid node structure". Luckily i back up religiously so i just reformatted and reinstalled the os. Since then the exact same thing has been happening on a more frequent basis (i only got 2 days use last time i reformatted). Since this all happened i have had it crash and had to reboot like 7 times. When i ran the apple hardware check everything checked out fine. Now that i am on winter break i can afford to be without it for awhile, is this a sign of the HD dying? Thanks!