I'll leave my 3rd generation iPod on the dock overnight, and it'll say "charged" (indicating a full charge) on the screen...I'll take it off for 30 seconds and replace it, to update my iTunes library, and instead of being fully charged, it'll spend an hour recharging, even though it was 100% charged when I took it off just a minute before! Is this normal? I don't remember anything like this happening with my 2nd gen. 'pod, and i know the 3g's have a few quirks. Should I be worried?