Hey! My brother also has an iPod touch and his one's going weird. After he fully charges his iPoT, It says that his iPod is full charged. So he uses it, and then the next time he uses it, it says that 20% of his battery is remaining and then runs out of battery within 10 minutes, even if he used the iPod for only 20 minutes from the previous use. Yes, he does switch it off properly and he hasn't dropped it or anything. His iPod is jailbroken in 1.1.2 firmware.