Has anyone had an issue waking their macbook up? I closed the lid last night and when i opened it this morning i just had a black screen. I pressed the track pad, power button and some keys and nothing happened. Then i though the battery may have been dead.. when i connected the power i heard the computer beep.. but still didnt come on.. Only until i pressed the power button/fingerprint and held it for a few seconds the screen actually came on.. is this normal?