Unfortunately, a PMU reset still didn't solve my dilemma. Getting nervous, I finally decided to take advantage of Apple's insulting "90 days of complementary support" to see if they could bail me out. Fortunately, after some troubleshooting, I learned my second lesson of the day: PowerBook and iBook adapters, if left plugged into a wall for too long, might need to actually be reset. This can easily be done by unplugging both of an adapter's ends for at least 60 seconds. We didn't delve into the inner workings of these power adapters for an explanation, but I've kept one plugged into a specific outlet in my apartment for probably at least a month or two, and I guess that might be just enough to make a power adapter a little confused in the head. So kids, remember: don't be like me. Keep your power adapter happy and light-show free by unplugging it from time to time.