Hey, my 13" MacBook (Late 2009) keeps turning off whenever the batter's percentage gets around 20%. One time it did this and I was just watching a video on YouTube and nothing else, nothing plugged in to the computer! When it turns off, it doesn't go in to sleep mode or anything, it instantly just turns off. When I turn it back on, the power indicator flashes and the hard drive clicks, and then it turns off again. If I try to turn it back on again, it does a normal boot with the Apple logo and stuff, and everything I had open before it shutdown was closed and the apps had quit. It has been doing this for about half a year. It has also been getting very hot over nothing. Its even doing that as I type this! Could someone please tell me what is going on?!?!? PLEASE. Specs: Processor - 2.13 GHz Intel Core 2 Duo Memory - 2 GB 800 MHz DDR2 SDRAM Hard Drive Size - 160.04 GB If you need more just ask. Thanks in Advance!