Just turned on my MacBook for the first time yesterday, clicked Macintosh HD and saw 33.78 available. Can anyone PLEASE tell me why? I understand the full capacity should be somewhere around 55, so why do I have only 50%? Also, while I'm at it, I upgraded to 10.4.9 and firefox, iTunes and some other programs which used to open on 1 or 2 bounces before the update now take 5-6 (i have 1GB ram by the way). Please advise me what to do. I am scared I broke something. Help!