About 98% of the time, my MBP stays at my desk, constantly hooked up to power. But a while ago I picked it up, and did some couch-surfing on battery-power. As I was using the computer, it suddently switched off. Just like that. I tried restarting the machine, and it started for 2-3 seconds and then turned off again. I removed the batter, and checked the battery-charge, and sure enough, it showed 2 leds. I tried turning the machine on again, but again it swithed off immediately. I took it back to my desk, hooked it up to power, and it worked just fine. It's recharging as we speak (it was down to about 40% charge, so there was plenty of power left). But as I check the battery health in iStat, it shows that it's down to 67%?? Any ideas?