Just got my new rMB (1.3, 512) and I love it. It's faster & more responsive than the reviews led me to expect, and I actually prefer the keyboard to my standard Apple kb. BUT...after an hour of use - just browsing the web and email - I'm down to 75% from a fully charged battery. This would mean 4 hours of battery life, which is abysmal. I have "put hard disk to sleep when possible" on, and screen at about 75% brightness. Anyone else having this problem? Do I have a defective battery? Any tips?