My iPod Touch is having a problem charging ever since it was on a dock. it takes about 10 hours to charge to 50% IF it charges, the battery goes down if i charge it while its on. very strange. also the only way it'll charge is if i take the charger and pull up on it while charging. ive tried 3 other usb cords so it must be a problem with the ipod. if anyone can help please reply. thanks!