I have a 2.0ghz core duo Macbook, and basically the problem is that the battery indicator now has a black X in it, indicating that there is no battery. This first occurred after I had intentionally ran down the battery until the system went to sleep, as Apple recommends for battery maintainence once a month. I have tried resetting the PRAM and reseating the battery, but the indicator still just shows a black X. From what I've read on Apple's website, I should bring it to...