My new macbook pro (2.5) turns on to the gray screen and then attempts to boot into OSX; however, instead of booting into the OS it turns off. Some times, instead of booting into OSX, it boots into Windows XP (I have it bootcamped). Any solutions or ideas as to what is wrong? It just froze up today, so I held down shutdown to force it out of the freeze. Now, I cannot boot up.